Manufacturing planning system, manufacturing planning method, and program

Abstract

Provided are a manufacturing planning system, a manufacturing planning method, and a program that make it possible to reduce shortfall of a product on a due date. A manufacturing planning system (4) is provided with a computation circuit (45) that can access data in a manufacturing plan (D1) for manufacturing a plurality of different products using a manufacturing facility that executes a plurality of steps. For a shortfall product, which is a product among the plurality of different products and for which a predicted number of finished product on a due date is less than a target number, the computation circuit (45): if the time remaining until the due date is equal to or greater than a manufacturing lead time, outputs a first change proposal for changing a manufacturing plan (D1) so as to increase the number of the shortfall product to manufacture in a first step that is first to be executed among the plurality of steps; and if the time remaining is less than the manufacturing lead time, outputs a second change proposal for changing the manufacturing plan (D1) so as to prioritize manufacturing of the shortfall product in a second step among the plurality of steps that is executed after the first step.

Description

Manufacturing planning system, manufacturing planning method, and program

[0001] The present disclosure relates to a manufacturing planning system, a manufacturing planning method, and a program.

[0002] Patent Document 1 discloses a production management device. In the production management device, a master storage unit stores a product master that defines a first period from the current day onward and a second period after the first period in association with product identification information. A production plan storage unit stores a product production plan. When a determination unit receives order information including product identification information, production quantity, delivery date, and a predetermined data category, the determination unit references the product master and, depending on the data category indicating the purpose of inputting the order information and the update content of the order information, determines that updating the production plan based on the order information is possible if the delivery date falls within the second period, and that updating the production plan based on the order information is not possible if the delivery date falls within the first period. A production plan update processing unit updates the production plan stored in the production plan storage unit based on the order information determined by the determination unit to be updateable.

[0003] Patent No. 5438211

[0004] In Patent Document 1, when updates to a production plan are accepted in real time, it is possible to prevent the occurrence of inaccurate plans.

[0005] Manufacturing sites require business management that reduces product inventory or shortens manufacturing lead times. While manufacturing delays can occur due to external factors, such as material procurement, or internal factors, such as equipment trouble or defects, products must be shipped to customers by their deadlines (due dates). However, the more complex the manufacturing process, the more difficult it becomes to determine whether a delay in shipping to customers is likely, and how to make up for the delay if one does occur. The technology described in Patent Document 1 cannot address such product manufacturing delays.

[0006] The present disclosure provides a manufacturing planning system, a manufacturing planning method, and a program that enable a reduction in the number of product shortages on deadlines.

[0007] A manufacturing planning system according to one aspect of the present disclosure includes an arithmetic circuit that can access data on a manufacturing plan for manufacturing a plurality of different products by a manufacturing facility that executes a plurality of processes, and the arithmetic circuit outputs a first modification plan to modify the manufacturing plan to increase the number of shortage products to be manufactured in a first process that is executed first among the plurality of processes, for a shortage product among the plurality of different products whose predicted number of finished products on the due date is less than a target number, when the remaining time until the due date is equal to or greater than the manufacturing lead time, and outputs a second modification plan to modify the manufacturing plan to prioritize the manufacturing of the shortage product in a second process that is executed after the first process among the plurality of processes, when the remaining time is less than the manufacturing lead time.

[0008] A manufacturing planning method according to one aspect of the present disclosure is executed by an arithmetic circuit that can access manufacturing plan data for manufacturing a plurality of different products by a manufacturing facility that performs a plurality of processes, and for a shortage product among the plurality of different products for which the predicted number of finished products on the due date is less than the target number, if the remaining time until the due date is equal to or greater than the manufacturing lead time, outputs a first modification plan to modify the manufacturing plan to increase the number of shortage products to be manufactured in a first process among the plurality of processes that is executed first, and if the remaining time is less than the manufacturing lead time, outputs a second modification plan to modify the manufacturing plan to prioritize the manufacturing of the shortage product in a second process among the plurality of processes that is executed after the first process.

[0009] A program according to one aspect of the present disclosure is a program for causing an arithmetic circuit to execute the above-described manufacturing planning method.

[0010] Aspects of the present disclosure allow for a reduction in the number of product shortages at due dates.

[0011] Schematic diagram of a manufacturing system according to one embodiment. Schematic diagram of a manufacturing facility for the manufacturing system according to the embodiment. Block diagram of an information management system for the manufacturing system according to the embodiment. Block diagram of a manufacturing planning system for the manufacturing system according to the embodiment. Graph showing an example of the distribution of manufacturing time for each process for each product. Graph showing an example of the distribution of residence time between processes for each product. Flowchart of determining changes to a manufacturing plan using a manufacturing planning system. Histogram showing the distribution of the predicted number of finished products. Flowchart of determining whether a product is insufficient or excessive using a manufacturing planning system. Histogram showing an example of the distribution of the difference between the predicted number of finished products and the target number. Histogram showing another example of the distribution of the difference between the predicted number of finished products and the target number. Graph of the difference between the predicted number and the target number for each product when the first change plan is implemented. Graph of the difference between the predicted number and the target number for each product when the first change plan is not implemented. Graph of the number of products manufactured when the second change plan is implemented and when the second change plan is not implemented.

[0012] [1. Embodiments] Hereinafter, embodiments of the present disclosure will be described, with reference to the drawings where appropriate. However, the following embodiments are merely examples for explaining the present disclosure, and are not intended to limit the present disclosure to the following content (e.g., the shape, dimensions, and arrangement of each component). Positional relationships, such as up, down, left, and right, are based on the positional relationships shown in the drawings unless otherwise specified. Each figure described in the following embodiments is a schematic diagram, and the ratios of the size and thickness of each component in each figure do not necessarily reflect the actual dimensional ratios. Furthermore, the dimensional ratios of each element are not limited to the ratios shown in the drawings.

[0013] In the following description, when it is necessary to distinguish between multiple components, prefixes such as "first" and "second" are added to the names of the components. However, when the components can be distinguished from each other by the symbols attached to them, the prefixes such as "first" and "second" may be omitted in consideration of readability of the text.

[0014] In the following description, when it is necessary to distinguish between multiple components, suffixes such as "-1" and "-2" are added to the symbols of the components. However, when it is not necessary to distinguish between multiple components, the suffixes "-1" and "-2" may be omitted to improve readability.

[0015] [1.1 Configuration] FIG. 1 is a schematic diagram of a manufacturing system 1 according to this embodiment. The manufacturing system 1 is used to manufacture a plurality of different products. The products are manufactured from raw materials through a plurality of processes. The products are not particularly limited, but include various items such as food, medicine, electrical appliances, jewelry, furniture, and vehicles. The products are not limited to finished products, but may also be parts. An example of a finished product is an automobile, and an example of a part is a core part of an automobile (such as a piston). The plurality of different products are identified and managed by identification information for each product. An example of identification information for each product is a product number.

[0016] The manufacturing system 1 includes a manufacturing facility 2, an information management system 3, a manufacturing planning system 4, and an information terminal 5.

[0017] The information terminal 5 is used by a user 6. The information terminal 5 may be realized, for example, by a personal computer (desktop computer, laptop computer), a mobile terminal (smartphone, tablet terminal, etc.), etc. The manufacturing system 1 can present information to the user 6 via the information terminal 5 and, if necessary, request the user 6 to input information.

[0018] The manufacturing facility 2 performs multiple processes to manufacture a product. The manufacturing facility 2 is a so-called factory. The manufacturing facility 2 includes equipment 20 that performs each process. The equipment 20 is selected appropriately depending on the product. The equipment 20 may include manufacturing equipment that enables manufacturing using various manufacturing technologies. Examples of manufacturing technologies include additive manufacturing technologies (material extrusion, liquid bath photopolymerization, material jetting, binder jetting, powder bed fusion, sheet lamination, directed energy deposition, etc.), subtractive manufacturing technologies (cutting, grinding, electrical discharge machining, casting, die casting, pressing, forging, sheet metal processing, etc.), formative (forming) manufacturing technologies (injection molding, extrusion molding, etc.), surface treatment technologies (coating, painting, plating, polishing, etc.), heat treatment technologies (sintering, cooling, etc.), joining technologies (ultrasonic bonding, thermal welding, mechanical bonding, adhesive bonding, etc.), and assembly technologies (part assembly, micro-imprinting, impregnation, etc.). The equipment 20 is not limited to manufacturing equipment, but may also include measurement equipment, inspection equipment, and transport equipment. Examples of the manufacturing facility 2 include a factory, a store, and a building (an entire building or a floor).

[0019] FIG. 2 is a schematic diagram of a manufacturing facility 2. The manufacturing facility 2 manufactures a number of different products. The manufacturing facility 2 employs a lot production system. Products are manufactured in lots. A lot is the smallest unit of production quantity for a product. The production quantity per lot is set appropriately depending on the product and may differ for each product.

[0020] The manufacturing process for each product includes multiple processes P1, P2, and P3. The manufacturing facility 2 includes, as equipment 20, equipment 21-1 to 21-4 that executes process P1, equipment 22-1 to 22-4 that executes process P2, and equipment 23-1 and 23-2 that execute process P3.

[0021] Equipment 21-1 to 21-4 manufacture work-in-progress M2 from raw material M1 of the product. The conditions for manufacturing work-in-progress M2 from raw material M1 are set appropriately for each product. Equipment 22-1 to 22-4 manufacture work-in-progress M3 from work-in-progress M2 of the product. The conditions for manufacturing work-in-progress M3 from work-in-progress M2 are set appropriately for each product. Equipment 23-1 and 23-2 manufacture finished product M4 from work-in-progress M3 of the product. The conditions for manufacturing finished product M4 from work-in-progress M3 are set appropriately for each product.

[0022] An input plan is determined for a first process, which is executed first among the multiple processes. The input plan indicates the schedule for manufacturing multiple different products in one or more first facilities that execute the first process. In other words, the input plan indicates which product lot will be manufactured in which first facility and when. In the manufacturing facility 2, process P1 is the first process, and facilities 21-1 to 21-4 are the first facilities. Raw material M1 is input into one of facilities 21-1 to 21-4 in accordance with the input plan.

[0023] Table 1 below shows an example of an input plan. In Table 1, "quantity" means the lot number of the product with the corresponding part number. For example, this means that on March 10th, equipment 21-1 will manufacture 100 units of the lot of product with part number A.

[0024]

[0025] In a second process, which is executed after the first process among the multiple processes, work-in-progress obtained in the process preceding the second process is added to the queue of one of the equipment of the second process. In the manufacturing facility 2, processes P2 and P3 are the second processes. Work-in-progress M2 obtained in process P1 preceding process P2 is added to the queue of one of the equipment 22-1 to 22-4 of process P2. Work-in-progress M3 obtained in process P2 preceding process P3 is added to the queue of one of the equipment 23-1 or 23-2 of process P3.

[0026] Table 2 below shows an example of a facility queue. In Table 2, "order" refers to the order in which the lots of the corresponding product part numbers are manufactured. For example, facility 22-1 will first manufacture one lot of product with part number A, and then the following lots will be manufactured in the order of part number A, part number A, part number B, part number B, part number C, and part number C.

[0027]

[0028] Typically, addition to the queue is performed on a first-in, first-out (FIFO) basis. The allocation of a lot manufactured in a process preceding the second process to a facility in the second process may be fixed or may change depending on the availability of the facility in the second process.

[0029] The information management system 3 manages information relating to the manufacture of a plurality of different products. Fig. 3 is a block diagram of the information management system 3. The information management system 3 includes an input device 31, an output device 32, a communication device 33, a storage device 34, and an arithmetic circuit 35. The information management system 3 can be realized, for example, by one or more servers.

[0030] The input device 31 includes one or more human-machine interfaces for inputting information. Examples of human-machine interfaces include a keyboard, a pointing device (such as a mouse or a trackball), a touchpad, a position input device such as a touch panel display, etc. The one or more human-machine interfaces of the input device 31 may be built into the information management system 3 or may be externally attached. In other words, the input device 31 may include a human-machine interface of the information management system 3 itself and a human-machine interface connected to the information management system 3.

[0031] The output device 32 includes one or more human-machine interfaces for outputting information. Examples of the human-machine interface include a display, a speaker, a touch panel display, and the like. The one or more human-machine interfaces of the output device 32 may be built into the information management system 3 or may be externally attached. In other words, the output device 32 may include a human-machine interface of the information management system 3 itself and a human-machine interface connected to the information management system 3.

[0032] The communication device 33 is used for communication through a communication network. The communication device 33 has one or more communication interfaces. The communication device 33 is connectable to a communication network and has the function of communicating through the communication network. The communication device 33 complies with a predetermined communication protocol. The predetermined communication protocol may be selected from various well-known wired and wireless communication standards.

[0033] The storage device 34 includes one or more storages (non-transitory storage media). The storages may be, for example, hard disk drives, optical drives, or solid-state drives (SSDs). The storages may be internal, external, or network-attached storage (NAS).

[0034] The information stored in the storage device 34 includes an order entry database DB1 and a production history database DB2. Fig. 3 shows a state in which the storage device 34 stores the order entry database DB1 and the production history database DB2. The order entry database DB1 and the production history database DB2 do not need to be stored in the storage device 34 at all times, but only need to be stored in the storage device 34 when needed by the arithmetic circuit 35.

[0035] The order database DB1 manages information regarding requests for the production of multiple different products by the manufacturing facility 2. The order database DB1 includes target quantity data for multiple products to be produced by the manufacturing facility 2. The target quantity data includes a due date and a target quantity. The due date is determined based on the delivery date or deadline of the product. The target quantity is the target number of products to be produced and corresponds to the number of products required on the due date. Table 3 below shows an example of target quantity data.

[0036]

[0037] The production performance database DB2 manages information relating to the results of manufacturing a plurality of different products at the manufacturing facility 2. The production performance database DB2 includes a performance database DB21 and a history database DB22.

[0038] The performance database DB21 shows the performance of the daily production number of each of a plurality of products. The following Table 2 shows an example of the performance database DB21. In Table 4, the current time is March 9th, and the columns for March 10th and onwards are blank.

[0039]

[0040] The history database DB22 shows the manufacturing history (past logs). The history database DB22 includes the product number, manufacturing conditions, and start and end times for each lot. Table 5 below shows an example of the history database DB22. Note that in Table 5, the start time is abbreviated as "Start" and the end time is abbreviated as "End." In Table 3, the current time is March 9th, and there are no times after March 10th. In Table 5, a lot number with an end time for process P3 indicates a completed lot for which a finished product M4 has been obtained. A lot number without an end time for process P3 indicates an in-process lot for which a finished product M4 has not yet been obtained. Among in-process lots, a lot number without a start time for process P3 but an end time for process P2 indicates a lot of work-in-process M3 waiting for process P3, and a lot number without a start time for process P2 but an end time for process P1 indicates a lot of work-in-process M2 waiting for process P2.

[0041]

[0042] The arithmetic circuit 35 is connected to the input device 31, the output device 32, and the communication device 33, and can access the storage device 34. The arithmetic circuit 35 can be realized, for example, by a computer system. The computer system includes one or more processors (microprocessors) and one or more memories. The one or more processors execute programs (stored in one or more memories or the storage device 34) to realize various functions of the information management system 3. The programs may be pre-recorded in the storage device 34, or may be provided via a telecommunications line such as the Internet, or recorded on a non-transitory recording medium such as a memory card.

[0043] The arithmetic circuit 35, for example, acquires information regarding requests for the production of multiple different products by the manufacturing facility 2 through communication via the communication device 33, and updates the order entry database DB1. The arithmetic circuit 35, for example, acquires information regarding the results of the production of multiple different products at the manufacturing facility 2 through communication via the communication device 33, and updates the manufacturing performance database DB2. As an example, the arithmetic circuit 35 can communicate with each piece of equipment 20 at the manufacturing facility 2 through the communication device 33 and acquire history data as needed.

[0044] The manufacturing planning system 4 is used to generate and modify manufacturing plans for manufacturing a plurality of different products by a manufacturing facility 2 that performs a plurality of processes. FIG. 4 is a block diagram of the manufacturing planning system 4. The manufacturing planning system 4 includes an input device 41, an output device 42, a communication device 43, a storage device 44, and an arithmetic circuit 45. The manufacturing planning system 4 may be realized, for example, by one or more servers. The configurations of the input device 41, the output device 42, the communication device 43, the storage device 44, and the arithmetic circuit 45 are similar to the configurations of the input device 31, the output device 32, the communication device 33, the storage device 34, and the arithmetic circuit 35.

[0045] The information stored in the storage device 44 includes a manufacturing plan D1, a manufacturing lead time prediction model D2, and a manufacturing planning program D3.

[0046] The manufacturing plan D1 includes an input plan (see Table 1) for a first process, which is executed first among the multiple processes, and an equipment queue (see Table 2) for a second process, which is executed after the first process among the multiple processes.

[0047] The manufacturing lead time prediction model D2 is a program that calculates the manufacturing lead time for a plurality of different products. The manufacturing of a plurality of different products involves a plurality of processes. The manufacturing lead time is calculated as the sum of the manufacturing time for each of the plurality of processes and the residence time for each of the plurality of inter-process periods. The residence time is the time taken from the end of the previous process to the start of the next process, and corresponds to the time difference between the end time of the previous process and the start time of the next process. Therefore, the manufacturing lead time prediction model D2 includes a manufacturing time prediction model D21 that calculates the manufacturing time for each of the plurality of processes, and a residence time prediction model D22 that calculates the residence time for each of the plurality of inter-process periods.

[0048] With respect to manufacturing facility 2, a plurality of different products are manufactured in processes P1, P2, and P3. Therefore, manufacturing lead time prediction model D2 includes three manufacturing time prediction models D21-1, D21-2, and D21-3 that calculate the manufacturing time for each of processes P1, P2, and P3, and two residence time prediction models D22-1 and D22-2 that calculate the residence time between processes P1 and P2 and between processes P2 and P3, respectively.

[0049] The manufacturing time prediction model D21 outputs the manufacturing time of the corresponding process in response to input of information about a product. In this embodiment, the manufacturing time prediction model D21 is a statistical model. The manufacturing time prediction model D21 may be constructed using the history database DB22 of the manufacturing performance database DB2. As shown in Table 6 below, the manufacturing time of each process can be extracted from the history database DB22 for each lot number of each product. The manufacturing time is the time from the start time to the end time of a process.

[0050]

[0051] Even for products with the same part number, the manufacturing time for each process varies for each lot. Therefore, the distribution of process manufacturing times can be obtained for multiple different products. FIG. 5 is a graph showing an example of the distribution of process manufacturing times for each product. FIG. 5 shows the distribution of manufacturing times for part numbers A, B, and C for process P1. Although this is merely an example, from FIG. 5, a normal distribution can be assumed for the distribution of manufacturing times. Therefore, if the manufacturing time is y, the manufacturing time prediction model D21 can be expressed by the following equation (1).

[0052]

[0053] N(μ,σ) represents a normal distribution with μ as the mean and σ as the standard deviation. Let X be the explanatory variable that is the factor that causes changes in the distribution of manufacturing time. The explanatory variable X can include the product number, manufacturing condition 1, and manufacturing condition 2. In this case, μ is expressed by the following formula (2), and σ is expressed by the following formula (3). W in formula (2) μ is the weighting coefficient multiplied by the explanatory variable X, and W in equation (3) σ is a weighting coefficient multiplied by the explanatory variable X.

[0054]

[0055] As shown in Table 6, explanatory variables X and manufacturing time y are obtained from the history database DB22. μ , W σ For example, by using the Markov Chain Monte Carlo method (MCMC) to perform Bayesian estimation, W μ , W σ In this way, the manufacturing time prediction model D21 can be constructed for each process.

[0056] The manufacturing time prediction model D21 provides a distribution of manufacturing times for the explanatory variable X. By using multiple random numbers, multiple predicted values ​​according to the distribution of manufacturing times corresponding to the explanatory variable X can be obtained. The number of predicted values ​​may be, for example, approximately 3,000. The manufacturing time may be determined by a representative value of these multiple predicted values. The representative value may be selected as appropriate from, for example, the average value, the mode value, the median value, or the like.

[0057] The residence time prediction model D22 outputs the residence time between the corresponding processes in response to input of information about a product. In this embodiment, the residence time prediction model D22 is a statistical model. The residence time prediction model D22 may be constructed using the history database DB22 of the production performance database DB2. As shown in Table 7 below, the residence time between each process can be extracted for each lot number of each product from the history database DB22. The residence time is the time from the end time of the previous process to the start time of the next process.

[0058]

[0059] Even for products with the same part number, the process manufacturing time varies for each lot. Therefore, the distribution of process manufacturing times can be obtained for multiple different products. Figure 6 is a graph showing an example of the distribution of process manufacturing times for each product. Figure 6 shows the distribution of residence times for part numbers A, B, and C between processes P1 and P2. Although this is merely an example, from Figure 6, a gamma distribution can be assumed for the distribution of residence times. Therefore, if the residence time is y, the residence time prediction model D22 can be expressed by the following equation (4).

[0060]

[0061] Ga(α, β) represents a gamma distribution with a shape parameter α and a scale parameter β. The explanatory variable that causes changes in the distribution of residence time is X. The explanatory variable X can include the product number, manufacturing condition 1, and manufacturing condition 2. In this case, α is expressed by the following formula (5), and β is expressed by the following formula (6). W in formula (5) α is the weighting coefficient multiplied by the explanatory variable X, and W in equation (6) β is a weighting coefficient multiplied by the explanatory variable X.

[0062]

[0063] As shown in Table 7, explanatory variables X and manufacturing time y are obtained from the history database DB22. α , W β For example, by using the Markov Chain Monte Carlo method (MCMC) to perform Bayesian estimation, W α , W β In this way, the residence time prediction model D22 can be constructed for each inter-process.

[0064] The dwell time prediction model D22 provides a distribution of dwell times for the explanatory variable X. By using a plurality of random numbers, a plurality of predicted values ​​according to the distribution of dwell times corresponding to the explanatory variable X can be obtained. The number of predicted values ​​may be, for example, about 3,000. The dwell time may be determined by a representative value of these plurality of predicted values. The representative value may be selected as appropriate from, for example, the mean value, the mode value, the median value, or the like.

[0065] The manufacturing lead time prediction model D2 can predict the manufacturing time for each of processes P1, P2, and P3, as well as the dwell time between processes P1 and P2 and between processes P2 and P3 for a product. The sum of the manufacturing time for each of processes P1, P2, and P3 and the dwell time between processes P1 and P2 and between processes P2 and P3 is the manufacturing lead time. On the other hand, the sum of the manufacturing time for processes P2 and P3 and the dwell time between processes P2 and P3 corresponds to the time required from the start to completion of process P2. Therefore, by using the manufacturing lead time prediction model D2, it is also possible to obtain the predicted time until product completion. In other words, because the manufacturing lead time prediction model D2 is divided into a manufacturing time prediction model D21 and a dwell time prediction model D22, it is possible to predict the time for any section.

[0066] In addition, when calculating the manufacturing lead time or the time of an arbitrary section, the representative values ​​of the manufacturing time prediction model D21 and the residence time prediction model D22 may be added, or the distribution of the manufacturing lead time or the time of an arbitrary section may be calculated from the manufacturing time prediction model D21 and the residence time prediction model D22, and the representative value of this distribution may be used.

[0067] The manufacturing plan program D3 is executed by the arithmetic circuit 45, causing the arithmetic circuit 45 to determine whether to change the manufacturing plan.

[0068] FIG. 7 is a flowchart showing the process performed by the manufacturing planning system 4 to determine whether to change the manufacturing plan.

[0069] The calculation circuit 45 acquires the due date and target quantity of the product (S11). More specifically, the calculation circuit 45 accesses the order database DB1 of the information management system 3 and acquires the due date and target quantity of the product that needs to be manufactured. For example, referring to Table 3, for product number B, the due date is March 15th and the target quantity is 12,000.

[0070] The calculation circuit 45 calculates the predicted number of finished products on the due date for the plurality of different products based on the manufacturing plan D1 (S12). The predicted number of finished products on the due date is given by the sum of the number of finished products already obtained, the predicted number of finished products on the due date based on the number of raw materials for the first process, and the predicted number of finished products on the due date based on the number of work-in-progress for the processes other than the first process among the plurality of processes.

[0071] The number of finished products that have already been obtained can be obtained from the record database DB21. For example, referring to Table 4, for product number B, the number of finished products is 3,405 as of March 9th.

[0072] The predicted number of finished products on the due date based on the number of work-in-progress items in processes other than the first process among the multiple processes can be calculated from the number of work-in-progress lots whose production will be completed by the due date. In other words, the predicted number of finished products based on the work-in-progress items can be obtained by multiplying the number of work-in-progress lots whose production will be completed by the due date by the number of products per lot.

[0073] To calculate the number of work-in-progress lots that will be completed by the due date, the completion time is predicted for each work-in-progress lot. The completion time is the time when the finished product is obtained and corresponds to the end time of the last process among multiple processes. The manufacturing lead time prediction model D2 is used to predict the completion time. Using the manufacturing lead time prediction model D2, the distribution of time for any interval can be obtained. Therefore, the distribution of the end time of the last process (i.e., the completion time) can be obtained based on the progress of the work-in-progress lot, for example, the final state and the time of the final state. For example, for lot number 100 in Table 5, the lot has progressed to process P3, and the final state is the start of process P3, which is the start time of process P3 (3 / 8 17:21). Therefore, the distribution of the manufacturing time for process P3 for lot number 100 is calculated using the manufacturing lead time prediction model D2, and this is added to the start time of process P3 to obtain the distribution of the completion time. Table 8 below shows an example of the distribution of the completion time for products with part number B for lot numbers 100 and below in Table 5. In Table 8, samples 1 to 3000 are the numbers of predicted values ​​sampled from the distribution of completion times for each lot number. The number of completed lots is the total number of lots for each sample whose completion time is before the due date, that is, the number of work-in-progress lots whose production will be completed by the due date. The distribution of the number of completed lots for samples 1 to 3000 indicates the distribution of the predicted number of finished products based on the work-in-progress. Note that the number of samples is not limited to 3000 and may be 1000, 5000, 10,000, etc., and may be set as appropriate.

[0074]

[0075] The predicted number of finished products on the due date based on the number of raw materials for the first process is the predicted number of finished products based on the input plan. The predicted number of finished products based on the input plan can be calculated from the number of lots in the input plan that will be completed by the due date. In other words, the predicted number of finished products based on the input plan can be obtained by multiplying the number of lots in the input plan that will be completed by the due date by the number of products per lot.

[0076] To determine the number of lots in the input plan that will be completed by the deadline, the completion time is predicted for each lot in the input plan. Based on the input plan, the scheduled production start time (i.e., the scheduled start time of the first process) for starting production of the product corresponding to each lot is determined for each lot. Table 9 below shows an example of the scheduled production start time for each lot.

[0077]

[0078] The manufacturing lead time prediction model D2 is used to predict the completion time. By using the manufacturing lead time prediction model D2, the distribution of the manufacturing lead time can be obtained, and therefore the distribution of the end time of the last process (i.e., the completion time) can be obtained based on the scheduled manufacturing start time. Table 10 below shows an example of the distribution of the completion time of product number B based on the input plan. In Table 10, samples 1 to 3000 are the numbers of predicted values ​​sampled from the distribution of the completion time for each lot number. The number of completed lots is the total number of lots for each sample whose completion time is before the due date. As a result, for product number B, the distribution of the predicted number of completed products based on the input plan can be obtained from the numbers of completed lots for samples 1 to 3000.

[0079]

[0080] In this way, by using the manufacturing lead time prediction model D2, a distribution of the predicted number of finished products based on work-in-progress and a distribution of the predicted number of finished products based on the input plan can be obtained. Therefore, the arithmetic circuit 45 calculates the distribution of the predicted number of finished products at the due date from the sum of the number of finished products at the current time, the distribution of the predicted number of finished products based on work-in-progress, and the distribution of the predicted number of finished products based on the input plan. Note that the number of finished products at the current time is not a distribution but a single value.

[0081] Table 11 below is a table showing the distribution of the predicted number of finished products on the due date for product number B. In Table 11, the predicted number was calculated assuming that the number of products per lot of product number B is 60.

[0082]

[0083] 8 is an example of a histogram showing the distribution of the predicted number of finished units on the due date for product number B. From FIG. 8, it can be seen that the predicted number ranges from about 10,000 to about 12,400, with the highest frequency at about 11,600.

[0084] The calculation circuit 45 calculates the distribution of the predicted number of completed products on the due date for each product.

[0085] Referring again to FIG. 7, the arithmetic circuit 45 then determines whether there is a surplus or shortage of products (S13). To determine whether there is a surplus or shortage of products, the predicted number of completed products on the due date is compared with the target number. In this embodiment, the distribution of the predicted number of completed products on the due date is obtained, and therefore, the distribution of the difference between the predicted number of completed products on the due date and the target number is used to determine whether there is a surplus or shortage of products.

[0086] FIG. 9 is a histogram showing an example of the distribution of the difference between the predicted number and the target number of finished products on the due date for product number B. The difference between the predicted number and the target number is positive when the predicted number is greater than the target number and negative when the predicted number is less than the target number. In FIG. 9, the target number is 12,000. In the histogram, the area where the difference between the predicted number and the target number is equal to or greater than 0 represents the probability that the predicted number will be equal to or greater than the target number, i.e., the probability that the required number of products will be prepared on the due date (probability of plan achievement). In FIG. 9, the probability of plan achievement is approximately 15%. In the histogram, the area where the difference between the predicted number and the target number is less than 0 represents the probability that the predicted number will be less than the target number, i.e., the probability that the required number of products will not be prepared on the due date.

[0087] Therefore, in the distribution of the difference between the predicted number and the target number, if the difference L1 between the predicted number and the target number at which the upper probability is a first value is L1 < 0, it is determined that there will be a shortage of products on the due date. The difference L1 between the predicted number and the target number at which the upper probability is a first value is used as the shortage number. The first value is, for example, 1%, but is not particularly limited and may be 2.5%, 5%, or the like, and may be set as appropriate. On the other hand, in the distribution of the difference between the predicted number and the target number, if the difference L2 between the predicted number and the target number at which the lower probability is a second value is L2 > 0 (positive), it is determined that there will be an excess of products on the due date. The difference L2 between the predicted number and the target number at which the lower probability is a second value is used as the excess number. The second value is, for example, 1%, but is not particularly limited and may be 2.5%, 5%, or the like, and may be set as appropriate.

[0088] 9, L1>0 and L2<0, so it is not determined that there will be a shortage or surplus of products on the due date. In this case, there is no shortage or surplus, and the predicted number can be considered to be equal to the target number.

[0089] FIG. 10 is a histogram showing another example of the distribution of the difference between the predicted number and the target number of finished products on the due date for product number B. In FIG. 10, the target number is 12,500, not 12,000. In the distribution of the difference between the predicted number and the target number in FIG. 10, L1<0, so it is determined that there will be a shortage of products on the due date. The absolute value of L1 is used as the shortage number. In this case, the predicted number may be given by target number - L1.

[0090] FIG. 11 is an explanatory diagram of yet another example of surplus / shortage determination using the distribution of the predicted number of finished products on a due date. In FIG. 11, the target number is 10,000, not 12,000. In the distribution of the difference between the predicted number and the target number in FIG. 11, L2 > 0, so it is determined that there is an excess of products on the due date. The absolute value of L2 is used as the excess number. In this case, the predicted number may be given by the target number + L2.

[0091] Referring again to Figure 7, the arithmetic circuit 45 then determines whether there is a shortage or excess of products (S13). Figure 12 is a flowchart showing the process for determining whether there is a shortage or excess of products.

[0092] The calculation circuit 45 determines whether there will be a shortage of products on the due date (S20). If L1<0 in the distribution of the difference between the predicted number of completed products on the due date and the target number for the product, it is determined that there will be a shortage of products on the due date.

[0093] In step S20, if it is determined that there will be a shortage of the product on the due date (S20: YES), the product is classified as a product with a shortage. Furthermore, it is determined whether the remaining time until the due date for the product is equal to or greater than the production lead time (referred to as production LT in FIG. 12) (S21).

[0094] In step S21, if the remaining time until the due date is equal to or greater than the manufacturing lead time (S21: YES), the product is classified as a first shortage product (S22). A first shortage product is a shortage product among multiple different products for which the predicted number of completed products on the due date is less than the target number, and for which the remaining time until the due date is equal to or greater than the manufacturing lead time. Thereafter, it is determined whether the determination of surplus or shortage has been completed for all products that need to be manufactured by the due date (S23).

[0095] In step S23, if it is determined that the surplus / shortage determination has been completed for all products that need to be manufactured by the deadline (S23: YES), the process ends; if not (S23: NO), step S20 is executed for the next product.

[0096] In step S21, if the remaining time until the due date is less than the manufacturing lead time (S21: NO), the product is classified as a second shortage product (S24). A second shortage product is a shortage product among multiple different products for which the predicted number of completed products on the due date is less than the target number, and for which the remaining time until the due date is less than the manufacturing lead time. Then, proceed to step S23.

[0097] If it is determined in step S20 that there is no shortage of product on the due date (S20: NO), it is determined whether there is an excess of product on the due date (S25). If L2>0 in the distribution of the difference between the predicted number of completed products on the due date and the target number for the product, it is determined that there is an excess of product on the due date.

[0098] In step S25, if it is determined that there is an excess of product on the due date (S25: YES), the product is classified as an excess product. Furthermore, it is determined whether the remaining time until the due date for the product is equal to or greater than the manufacturing lead time (S26).

[0099] In step S26, if the remaining time until the due date is equal to or greater than the manufacturing lead time (S26: YES), the product is classified as a first surplus product (S27). A first surplus product is an surplus product among a plurality of different products, the predicted number of completed products on the due date exceeds the target number, and the remaining time until the due date is equal to or greater than the manufacturing lead time. Then, the process proceeds to step S23.

[0100] In step S26, if the remaining time until the due date is less than the manufacturing lead time (S26: NO), the product is classified as a second surplus product (S28). A second surplus product is an surplus product among multiple different products, the predicted number of completed products on the due date exceeds the target number, and the remaining time until the due date is less than the manufacturing lead time. Then, proceed to step S23.

[0101] If it is determined in step S25 that there is no excess product on the due date (S25: NO), the product is classified as a normal product, and then the process proceeds to step S23.

[0102] In this way, products that need to be manufactured by the deadline are classified into first shortage products, second shortage products, first excess products, second excess products, and normal products based on the judgment of excess or shortage.

[0103] The first and second shortage products are shortage products for which the predicted number of finished products on the due date is less than the target number. For the first shortage product, the remaining time until the due date is equal to or greater than the manufacturing lead time. Therefore, by increasing the number of first shortage products manufactured in the first process, which is executed first among the multiple processes, it is expected that the number of products in short supply on the due date will be reduced. For the second shortage product, the remaining time until the due date is less than the manufacturing lead time. Therefore, even if the number of second shortage products manufactured in the first process is increased, it is not expected that the number of products in short supply on the due date will be reduced. For the second shortage product, by prioritizing the manufacture of the second shortage product in the second process, which is executed after the first process among the multiple processes, it is possible to prioritize the completion of the manufacture of products in the middle of production (work-in-progress), thereby it is expected that the number of products in short supply on the due date will be reduced.

[0104] The first excess product and the second excess product are excess products whose predicted number of finished products on the due date exceeds the target number. When prioritizing the production of shortage products, it is preferable to postpone the production of the excess product. For the first excess product, the remaining time until the due date is equal to or greater than the production lead time, while for the second excess product, the remaining time until the due date is less than the production lead time. Therefore, the first excess product is more likely to be able to secure the target number on the due date even if its input to the first equipment is postponed compared to the second excess product. For the second excess product, it is desirable to monitor the predicted number of finished products on the due date so that the target number can be secured on the due date even if its input to the first equipment is postponed. Therefore, the first excess product is selected with priority over the second excess product. In this embodiment, the first excess product is selected as a candidate for postponement of production relative to the shortage product in at least one of the first and second processes. The second excess product is selected as a candidate for postponement of production relative to the shortage product in the second process.

[0105] Table 12 below shows an example of the results of determining whether a product is insufficient or insufficient. In Table 12, if the number of surpluses or shortages is positive, it means that the number is insufficient, and if it is negative, it means that the number is insufficient.

[0106]

[0107] In this way, the arithmetic circuit 45 detects a product that is in short supply (the first or second product that is in short supply) from among the multiple different products based on a comparison between the predicted number of each of the multiple different products and the target number.

[0108] Referring again to Figure 7, the arithmetic circuit 45 then determines whether the product is a product in shortage, that is, whether the product is a first or second product in shortage (S14).

[0109] In step S14, if the product is a first shortage product (S14: first shortage product), a first change plan is generated and output (S15).

[0110] The first modification plan modifies the production plan to increase the production quantity of the shortage product (first shortage product) in a first process, which is executed first among multiple processes. The production facility 2 includes one or more first equipment (equipment 21-1 to 21-4) that executes the first process. The production plan includes an input plan that indicates the planned production of multiple different products in the one or more first equipment. Therefore, the number of products to be produced in the first process is determined by the input plan. Therefore, the first modification plan modifies the input plan to increase the production quantity of the first shortage product. In this embodiment, the first modification plan includes increasing the lot size of the first shortage product by a predetermined number in the input plan. The predetermined number is determined based on the number per lot of the first shortage product and the difference between the predicted number and the target number of the first shortage product (shortage number).

[0111] 13 and 14 are explanatory diagrams of the first modification plan. In particular, Fig. 13 is a schematic diagram of the investment plan before the first modification plan is applied, and Fig. 14 is a schematic diagram of the investment plan after the first modification plan is applied.

[0112] 13 shows raw materials M1 for products with part numbers C, D, and E that are input in lots to facilities 21-1, 21-2, 21-3, and 21-4 that perform process P1, which is the first process. In FIG. 13, five units of raw material M1 with part number C are input sequentially, one lot at a time, to facility 21-1. Five units of raw material M1 with part number D are input sequentially, one lot at a time, to facility 21-2. Three units of raw material M1 with part number E are input sequentially, one lot at a time, to facility 21-3, followed by two units of raw material M1 with part number C, one lot at a time, to facility 21-3. One lot of raw material M1 with part number C is input sequentially, and then four units of raw material M1 with part number D are input sequentially, one lot at a time, to facility 21-4.

[0113] In Table 12, product number E is the first shortage product. Therefore, the first change plan modifies the production plan to increase the production quantity of product number E by a predetermined number in the production plan. The predetermined number is determined based on the number of shortage products per lot and the difference between the predicted number and the target number of shortage products (shortage number). In Table 12, the shortage quantity of product number E is 1,000. If the number of products with product number E per lot is 200, the predetermined number is 5.

[0114] In the first modification plan, when increasing the production quantity of the first shortage product, the lot of the excess product is changed to a lot of the first shortage product. The excess product is selected from the first excess product. In Table 12, product number D is the first excess product. Therefore, as shown in FIG. 14, the first modification plan changes a lot of five units of product number D to a lot of five units of product number E.

[0115] Outputting the first change proposal includes transmitting data of the first change proposal to the information terminal 5 via the communication device 43. This allows the information terminal 5 to present the first change proposal to the user 6. The user 6 can change the production plan in accordance with the first change proposal. By adopting the first change proposal, production of the first shortage product is prioritized, thereby making it possible to reduce the shortage quantity by the due date.

[0116] Referring again to Figure 7, after step S15, it is determined whether or not the determination of shortage products has been completed for all products that need to be manufactured by the deadline (S16).

[0117] In step S16, if it is determined that the determination of whether or not there is a shortage of all products that need to be manufactured by the deadline has been completed (S16: YES), the process ends, and if not (S16: NO), step S14 is executed for the next product.

[0118] In step S14, if the product is a second shortage product (S14: second shortage product), a second change plan is generated and output (S17).

[0119] The second modification plan modifies the production plan to prioritize the production of the shortage product (second shortage product) in a second process, which is executed after the first process among the multiple processes. The number of products to be produced in the second process is determined by the queue of the second equipment that executes the second process. Therefore, the second modification plan adds the lot of the second shortage product to the top of the queue of the second equipment so that the second shortage product is preferentially produced in the second equipment.

[0120] Figures 15, 16 and 17 are illustrative diagrams of the second modification plan. In particular, Figure 15 is a schematic diagram of the queue before the second modification plan is applied, and Figures 16 and 17 are schematic diagrams of the queue after the second modification plan is applied.

[0121] 15 shows the queues of facilities 22-1, 22-2, 22-3, and 22-4 that perform process P2, the second process. In FIG. 15, four lots of work-in-process product M2 with part number C are lined up in the queue of facility 22-1. In the queue of facility 22-2, one lot of work-in-process product M2 with part number C and one lot of work-in-process product M2 with part number B are lined up in this order. In the queue of facility 22-3, one lot of work-in-process product M2 with part number B is lined up. In the queue of facility 22-4, one lot of work-in-process product M2 with part number B and two lots of work-in-process product M2 with part number C are lined up in this order.

[0122] Normally, since it is first-in, first-out, work-in-progress M2 is added to the end of the queue of one of the facilities 22-1 to 22-4. In Figure 15, work-in-progress M2 with part number B is added to the end of the queue of the facility 22-2 according to the first-in, first-out rule.

[0123] In Table 12, the product with part number B is the second product in shortage. Therefore, in the second modification, work-in-progress item M2 with part number B is added to the head of the queue of any of the equipment 22-1 to 22-4, rather than the tail. In Figure 16, work-in-progress item M2 with part number B is added to the head of the queue of equipment 22-4.

[0124] Here, the second modification preferably adds the lot of the second shortage product to the head of a queue of the equipment 22-1 to 22-4 that contains a lot of a product different from the second shortage product among the multiple different products. In particular, the second modification preferably adds the lot of the second shortage product to the head of a queue of the equipment 22-1 to 22-4 that contains a lot of an excess product. The excess product is selected from the first excess product or the second excess product. The first excess product is selected with priority over the second excess product.

[0125] In FIG. 17, the queue for equipment 22-1 contains three lots of work-in-progress M2 with part number A and one lot of work-in-progress M2 with part number C, in that order. The queue for equipment 22-4 contains one lot of work-in-progress M2 with part number B and two lots of work-in-progress M2 with part number A, in that order. Therefore, work-in-progress M2 with part number B should be added to the head of either the queue for equipment 22-1, 22-2, or 22-4 among the queues for equipment 22-1 to 22-4. In Table 12, item number A is the second excess product. Therefore, the queues for equipment 22-1 and 22-4 contain the second excess product. Therefore, work-in-progress M2 with part number B should be added to the head of either the queue for equipment 22-1 or 22-4 among the queues for equipment 22-1, 22-2, and 22-4. Here, if there are multiple queues containing lots of excess products, the second modification preferably adds the lot of the second shortage product to the head of the queue with the largest total number of excess product lots among the multiple queues. The number of excess product lots contained in the queue of equipment 22-1 is 3, and the number of excess product lots contained in the queue of equipment 22-2 is 2. Therefore, work-in-progress M2 with part number B should be added to the head of the queue of equipment 22-1.

[0126] Outputting the second change proposal includes transmitting data of the second change proposal to the information terminal 5 via the communication device 43. This allows the information terminal 5 to present the second change proposal to the user 6. The user 6 can change the production plan in accordance with the second change proposal. By adopting the second change proposal, production of the second shortage product is prioritized, thereby making it possible to reduce the number of products that are in short supply by the deadline.

[0127] Referring again to Figure 7, after step S17, the process proceeds to step S16.

[0128] In step S14, if the product is neither the first shortage product nor the second shortage product (S14: NO), the process proceeds to step S16.

[0129] In this way, for product number E, the predicted quantity is likely to fall short of the target quantity, but the remaining time is equal to or greater than the manufacturing lead time, so the manufacturing planning system 4 proposes changing the manufacturing plan to increase the input of raw material M1 (first modification proposal). For product number B, the predicted quantity is likely to fall short of the target quantity, but the remaining time is shorter than the manufacturing lead time, so the manufacturing planning system 4 outputs a second modification proposal to change the manufacturing plan to expedite the manufacturing of work-in-process items M2 and M3. For products A and D, the predicted quantity is likely to exceed the target quantity, so the manufacturing planning system 4 considers them candidates for postponement of manufacturing after products B and E. In particular, because the remaining time for product number D is equal to or greater than the manufacturing lead time, while the remaining time for product number A is shorter than the manufacturing lead time, the manufacturing of product number D is postponed after the manufacturing of product number A. In this way, the manufacturing planning system 4 determines the manufacturing priorities of multiple different products based on a comparison between the predicted quantity and the target quantity and a comparison between the remaining time and the manufacturing lead time.

[0130] [1.2 Evaluation] A simulation was performed to confirm the effect of the first modification proposal to the manufacturing plan by the manufacturing planning system 4 described above. Fig. 18 is a graph showing the difference between the predicted number and the target number for each product when the first modification proposal is implemented. Fig. 19 is a graph showing the difference between the predicted number and the target number for each product when the first modification proposal is not implemented. In Figs. 18 and 19, the horizontal axis represents the product part number, the right vertical axis represents the target number, and the left vertical axis represents the difference between the predicted number and the target number (predicted number - target number).

[0131] In Figures 18 and 19, G1 is a graph showing the target number of products, and it can be seen that the larger the target number, the larger the difference between the predicted number and the target number tends to be. For part numbers included in the range enclosed by R1, the predicted number is much lower than the target number, and it is considered relatively likely that there will be an insufficient number of products produced. For part numbers included in the range enclosed by R2, the predicted number is much higher than the target number, and it is considered relatively likely that there will be an excess number of products produced. Comparing Figure 18, in which the first modification plan was implemented, with Figure 19, in which the first modification plan was not implemented, it was confirmed that Figure 18 tends to have a smaller difference between the predicted number and the target number for both part numbers included in R1 and R2.

[0132] From the above, it was confirmed that implementing the first change plan would make it possible to reduce the number of product shortages on the due date. It was also confirmed that by prioritizing products that are in short supply over products that are in excess, it would make it possible to reduce the number of product surpluses on the due date.

[0133] A simulation was conducted to confirm the effect of the second modification of the manufacturing plan by the above-described manufacturing planning system 4. In the verification experiment, the number of each product to be manufactured was verified in two cases: when the second modification was implemented and multiple different products were manufactured in a relatively short period of time, and when multiple different products were manufactured in a relatively short period of time without implementing the second modification.

[0134] Figure 20 is a graph comparing the production volume of each product within a short period (e.g., three days) within the lead time when the second change plan is implemented and when it is not implemented. In Figure 20, the production volume when the change plan is not implemented and the production volume when it is implemented are shown as pairs of filled and open boxes, respectively. Products with part numbers included in the range enclosed by R3 are shortage products, and products with part numbers included in the range enclosed by R4 are surplus products. Figure 20 confirms that by implementing the second change plan, the production volume of shortage products increases and the production volume of surplus products decreases within a short period within the lead time.

[0135] From the above, it was confirmed that implementing the second change plan would make it possible to reduce the number of product shortages on the due date. It was also confirmed that by prioritizing products that are in short supply over products that are in excess, it would make it possible to reduce the number of product surpluses on the due date.

[0136] In this way, the manufacturing planning system 4 makes it possible to reduce excess or shortage of products. For example, by setting a certain margin relative to the target number, it becomes possible to manufacture products without excess or shortage. This makes it possible to reduce unnecessary product inventory and shorten the product manufacturing lead time.

[0137] 1.3 Effects, etc. The manufacturing planning system 4 described above includes an arithmetic circuit 45 that can access data on the manufacturing plan D1 for manufacturing a plurality of different products by a manufacturing facility 2 that performs a plurality of processes. For a shortage product among the plurality of different products, for which the predicted number of finished products on the due date is less than the target number, the arithmetic circuit 45 outputs a first modification plan for modifying the manufacturing plan D1 to increase the number of shortage products to be manufactured in a first process, which is executed first among the plurality of processes, if the remaining time until the due date is equal to or greater than the manufacturing lead time. Alternatively, if the remaining time is less than the manufacturing lead time, the arithmetic circuit 45 outputs a second modification plan for modifying the manufacturing plan D1 to prioritize the manufacturing of the shortage product in a second process, which is executed after the first process, among the plurality of processes. This configuration makes it possible to reduce the number of products that are in short supply on the due date.

[0138] In the manufacturing planning system 4, the manufacturing facility 2 includes one or more first pieces of equipment (equipment 21-1 to 21-4) that perform a first process (process P1). The manufacturing plan D1 includes an input plan that indicates a schedule for manufacturing a plurality of different products at the one or more first pieces of equipment. The first change plan includes increasing the lot size of a product that is in short supply by a predetermined number in the input plan. This configuration makes it possible to reduce the number of products that are in short supply on the due date.

[0139] In the manufacturing planning system 4, the predetermined number is determined based on the number of shortage products per lot and the difference between the predicted number and the target number of shortage products. This configuration enables further reduction in the number of product shortages on the due date.

[0140] In the manufacturing planning system 4, the first change proposal includes changing a lot of an excess product in the input plan to a lot of a shortage product. The excess product is a product of multiple different products whose predicted quantity exceeds the target quantity. This configuration makes it possible to reduce the shortage and excess quantity of products on the due date.

[0141] In the manufacturing planning system 4, the manufacturing facility 2 includes one or more second equipment (equipment 22-1 to 22-4, 23-1, 23-2) that executes second processes (processes P2 and P3). The manufacturing plan D1 includes queues for the one or more second equipment. The second proposed change includes adding a lot of a product that is in short supply to the head of the queue for the one or more second equipment. This configuration makes it possible to reduce the number of product shortages and surpluses on due dates.

[0142] In the manufacturing planning system 4, the second modification includes adding the lot of the shortage product to the head of a queue of one or more second facilities that contains a lot of a product different from the shortage product among a plurality of different products. This configuration makes it possible to reduce the shortage and surplus of the product on the due date.

[0143] In the manufacturing planning system 4, the second modification includes adding a lot of the shortage product to the head of a queue of one or more second facilities that contains a lot of the excess product. The excess product is a product among a plurality of different products whose forecast quantity exceeds a target quantity. This configuration enables a reduction in the shortage and excess quantity of the product at the due date.

[0144] In the case where there are multiple queues containing lots of excess products in the manufacturing planning system 4, the second modification involves adding the lot of the shortage product to the head of the queue among the multiple queues that has the largest total number of lots of excess products. This configuration makes it possible to reduce the number of shortages and excesses of products on the due date, while also preventing delays in the production of regular products that were originally being produced smoothly from being postponed due to the priority being given to the shortage product.

[0145] In the manufacturing planning system 4, the arithmetic circuit 45 detects a product that is in short supply from among the plurality of different products based on a comparison between the predicted number and the target number of each of the plurality of different products. This configuration can save the user the trouble of specifying a product that is in short supply from among the plurality of different products.

[0146] In the manufacturing planning system 4, the arithmetic circuit 45 calculates the predicted number of multiple different products based on the manufacturing plan. The predicted number is given by the sum of the number of finished products already obtained, the predicted number of finished products on the due date based on the number of raw materials for the first process, and the predicted number of finished products on the due date based on the number of work-in-progress items for processes other than the first process among the multiple processes. This configuration saves the user the trouble of calculating the predicted number of multiple different products.

[0147] In the manufacturing planning system 4, the arithmetic circuit 45 calculates the manufacturing lead time of the shortage product using the manufacturing lead time prediction model D2. The manufacturing lead time prediction model D2 includes a manufacturing time prediction model D21 that calculates the manufacturing time for each of a plurality of processes and a flow time prediction model D22 that calculates the flow time between each of a plurality of processes. The manufacturing lead time of the shortage product is determined based on the manufacturing time output from the manufacturing time prediction model D21 for the shortage product and the flow time output from the flow time prediction model D22 for the shortage product. This configuration can improve the accuracy of determining whether to apply the first change plan or the second change plan, and enables further reduction in the number of products that are in short supply by the due date.

[0148] In the manufacturing planning system 4, when the period for an excess product, the predicted number of which exceeds the target number among a plurality of different products, is equal to or longer than the manufacturing lead time, the calculation circuit 45 determines the excess product as a candidate for postponing production of the excess product relative to the shortage product in at least one of the first and second processes. This configuration makes it possible to reduce the shortage and excess number of products on the due date.

[0149] In the manufacturing planning system 4, if an excess product, the predicted number of which exceeds the target number among a plurality of different products, has a period shorter than the manufacturing lead time, the calculation circuit 45 determines the excess product as a candidate for postponing manufacturing of the excess product in the second process, rather than the shortage product. This configuration makes it possible to reduce the shortage and excess number of products on the due date.

[0150] The manufacturing planning system 4 described above can be said to execute the following method (manufacturing planning method). The manufacturing planning method is executed by an arithmetic circuit 45 that can access data on a manufacturing plan D1 for manufacturing a plurality of different products by a manufacturing facility 2 that performs a plurality of processes. For a shortage product among the plurality of different products, for which the predicted number of finished products on a due date is less than the target number, if the remaining time until the due date is equal to or greater than the manufacturing lead time, the method outputs a first modification plan to modify the manufacturing plan D1 to increase the number of shortage products to be manufactured in a first process, which is executed first among the plurality of processes. If the remaining time is less than the manufacturing lead time, the method outputs a second modification plan to modify the manufacturing plan D1 to prioritize the production of the shortage product in a second process, which is executed after the first process, among the plurality of processes. This configuration makes it possible to reduce the number of products that are in short supply on the due date.

[0151] The manufacturing planning method executed by the manufacturing planning system 4 can be realized by the arithmetic circuitry 45 executing the manufacturing planning program D3. The manufacturing planning program D3 is a computer program for causing the arithmetic circuitry 45 to execute the manufacturing planning method. This configuration makes it possible to reduce the number of products that are in short supply on a due date.

[0152] [2. Modifications] The embodiments of the present disclosure are not limited to the above-described embodiments. The above-described embodiments can be modified in various ways depending on the design, etc., as long as the object of the present disclosure can be achieved. Modifications of the above-described embodiments are listed below. The modifications described below can be applied in appropriate combinations.

[0153] In one modified example, the manufacturing facility 2 is not limited to the configuration shown in Figure 2. The content and number of processes performed in the manufacturing facility 2 are not particularly limited and are set appropriately depending on the product. The number of pieces of equipment for each process in the manufacturing facility 2 is also not particularly limited and is set appropriately depending on the scale of the manufacturing facility 2, etc.

[0154] In one variant, the calculation circuit 45 may output the first change plan or the second change plan to the manufacturing facility 2 instead of outputting it to the information terminal 5, and automatically reflect the changes to the manufacturing plan D1 in the production of products at the manufacturing facility 2.

[0155] In one variant, the second step may be any one or more of two or more steps among the plurality of steps that are executed after the first step, and it is not necessarily required that all of the two or more steps be used as the second step.

[0156] In one modified example, the manufacturing lead time prediction model D2 does not necessarily include the manufacturing time prediction model D21 and the residence time prediction model D22, but may include only one of them. The manufacturing lead time does not necessarily have to be calculated from the manufacturing time and the residence time, and the manufacturing lead time prediction model D2 may be constructed as a model in which the objective variable is the manufacturing lead time and the explanatory variable is product information.

[0157] In one modified example, the method for constructing the manufacturing time prediction model D21 is not limited to the above embodiment. The manufacturing time prediction model D21 can be constructed using various conventionally known prediction model construction methods, such as determining the mean and variance by linear regression. In the above embodiment, the assumed distribution of the manufacturing time is not limited to a normal distribution, and may be determined in accordance with actual data.

[0158] In one modification, the method for constructing the residence time prediction model D22 is not limited to the above embodiment. α , W β In the above embodiment, the distribution assumed for the distribution of the residence time is not limited to the gamma distribution, and may be determined in accordance with actual data.

[0159] In one variant, the manufacturing lead time prediction model D2 may be constructed using a trained model.

[0160] In one variant, the manufacturing lead time prediction model D2 is not required. For example, the manufacturing lead time of each product may be extracted from a database indicating the manufacturing lead time of each product.

[0161] In one modified example, the arithmetic circuitry 45 does not necessarily need to calculate the distribution of the predicted number of products. Furthermore, the arithmetic circuitry 45 does not necessarily need to calculate the predicted number of products. The arithmetic circuitry 45 may obtain the predicted number of products from an external device via communication or the like.

[0162] In one modified example, the arithmetic circuitry 45 does not necessarily need to detect a missing product from a plurality of different products. The arithmetic circuitry 45 may obtain information identifying a missing product from an external device via communication or the like.

[0163] In one variation, the first modification does not necessarily involve changing a lot of an excess product to a lot of a shortage product in the input plan. If the shortage number of shortage products is greater than the excess number of a single excess product, the first modification may change lots of multiple types of excess products to lots of the shortage product. Alternatively, the first modification may simply involve adding lots of the shortage product to the input plan.

[0164] In one variant, the second modification may include adding the lot of the missing product to one of the queues of one or more second facilities that would result in the fewest product changeovers if the lot of the missing product were added to the head of the queue. In this regard, refer to FIG. 17 . In FIG. 17 , assume that a work-in-process item M2 with part number A is being manufactured at facility 22-1. In this case, if a work-in-process item M2 with part number B, which is a lot of the missing product, is added to the head of the queue of facility 22-1, it becomes necessary to switch facility 22-1 from the setting for part number A to the setting for part number B. Then, after the work-in-process item M2 with part number B is manufactured, it becomes necessary to switch facility 22-1 from the setting for part number B to the setting for part number A. Such an increase in the number of setting changes can contribute to a decrease in manufacturing efficiency. From this perspective, if facility 22-4 is manufacturing the work-in-process item M2 with part number B in FIG. 17 , it is conceivable to add the lot of work-in-process item M2 with part number B to the head of the queue of facility 22-4, rather than facility 22-1. In this case, it is not necessary to change the settings when adding a lot of the shortage product, and this is expected to improve manufacturing efficiency. When selecting the queue to which the shortage product lot is added at the head, it is preferable to also take into consideration the number of times the settings of the second equipment are changed.

[0165] In one variant, the multiple processes may include two or more processes executed after the first process. In the above embodiment, processes P2 and P3 are executed after process P1, which is the first process. Depending on the remaining time, even if process P2 is designated as the second process and production of the missing product is prioritized, the missing product may not be completed by the due date. In this case, process P3, which is executed after process P2, may be selected as the second process and production of the missing product may be prioritized. Therefore, the second modification plan includes selecting, as the second process, a process executed later from two or more processes executed after the first process among the multiple processes, the shorter the remaining time. More preferably, the second modification plan includes selecting, as the second process, a process executed later from two or more processes executed after the first process among the multiple processes, the process whose time required to complete the missing product is equal to or shorter than the remaining time. The time required from the start of a process to the completion of the missing product may be calculated using the manufacturing lead time prediction model D2. This enables further reduction in the number of products in short supply by the due date.

[0166] In one modified example, the manufacturing planning system 4 may be realized by a computer system such as a plurality of servers. It is not necessary that the plurality of functions (components) of the manufacturing planning system 4 be integrated into a single housing, and the components of the manufacturing planning system 4 may be distributed across a plurality of housings. Furthermore, at least some of the functions of the manufacturing planning system 4, for example, some of the functions of the arithmetic circuit 45, may be realized by the cloud (cloud computing) or the like.

[0167] [3. Aspects] As is clear from the above-described embodiment and modifications, the present disclosure includes the following aspects.

[0168] [Aspect 1] A manufacturing planning system comprising an arithmetic circuit that can access data on a manufacturing plan for manufacturing a plurality of different products by a manufacturing facility that executes a plurality of processes, wherein the arithmetic circuit: for a shortage product among the plurality of different products for which the predicted number of finished products on a due date is less than a target number, when the remaining time until the due date is equal to or greater than a manufacturing lead time, outputs a first modification proposal to modify the manufacturing plan to increase the number of the shortage product to be manufactured in a first process among the plurality of processes that is executed first; and when the remaining time is less than the manufacturing lead time, outputs a second modification proposal to modify the manufacturing plan to prioritize the manufacturing of the shortage product in a second process among the plurality of processes that is executed after the first process.

[0169] [Aspect 2] The manufacturing planning system of Aspect 1, wherein the manufacturing facility includes one or more first pieces of equipment that perform the first process, the manufacturing plan includes an input plan that indicates a schedule for manufacturing the plurality of different products at the one or more first pieces of equipment, and the first change proposal includes increasing the lot of the shortage product by a predetermined number in the input plan.

[0170] [Aspect 3] The manufacturing planning system of Aspect 2, wherein the predetermined number is determined based on the number of the shortage product per lot and the difference between the predicted number and the target number of the shortage product.

[0171] [Aspect 4] The manufacturing planning system of Aspect 2 or 3, wherein the first change plan includes changing a lot of an excess product to a lot of the shortage product in the input plan, and the excess product is a product of the plurality of different products whose predicted quantity exceeds the target quantity.

[0172] [Aspect 5] The manufacturing planning system according to any one of Aspects 1 to 4, wherein the manufacturing facility includes one or more second pieces of equipment that perform the second process, the manufacturing plan includes a queue for the one or more pieces of second equipment, and the second change plan includes adding the lot of the shortage product to the head of the queue for the one or more pieces of second equipment.

[0173] [Aspect 6] The manufacturing planning system of Aspect 5, wherein the second change proposal includes adding the lot of the shortage product to the head of a queue of the one or more second facilities that includes a lot of a product different from the shortage product among the plurality of different products.

[0174] [Aspect 7] The manufacturing planning system of Aspect 5 or 6, wherein the second change plan includes adding the lot of the shortage product to the head of a queue of the one or more second facilities that includes a lot of the excess product, and the excess product is a product of the plurality of different products whose forecasted quantity exceeds the target quantity.

[0175] [Aspect 8] The manufacturing planning system of Aspect 7, wherein, when there are multiple queues containing the lot of the excess product, the second modification includes adding the lot of the shortage product to the head of the queue among the multiple queues that has the largest total number of lots of the excess product.

[0176] [Aspect 9] The manufacturing planning system according to any one of Aspects 1 to 8, wherein the arithmetic circuit detects the shortage product from the plurality of different products based on a comparison between the predicted number and the target number of each of the plurality of different products.

[0177] [Aspect 10] The manufacturing planning system of Aspect 9, wherein the arithmetic circuit determines the predicted number of the plurality of different products based on the manufacturing plan, and the predicted number is given by the sum of the number of finished products that have already been obtained, the predicted number of finished products on the due date based on the number of raw materials for the first process, and the predicted number of finished products on the due date based on the number of work-in-progress for processes other than the first process among the plurality of processes.

[0178] [Aspect 11] The manufacturing planning system according to any one of Aspects 1 to 10, wherein the arithmetic circuit determines the manufacturing lead time of the shortage product using a manufacturing lead time prediction model, and the manufacturing lead time prediction model includes a manufacturing time prediction model that determines a manufacturing time for each of the plurality of processes and a flow time prediction model that determines a flow time between each of the plurality of processes, and the manufacturing lead time of the shortage product is determined based on the manufacturing time output from the manufacturing time prediction model for the shortage product and the flow time output from the flow time prediction model for the shortage product.

[0179] [Aspect 12] The manufacturing planning system according to any one of Aspects 1 to 11, wherein, when the period is equal to or longer than the manufacturing lead time for an excess product among the plurality of different products, the excess product is a candidate for postponement of manufacturing later than the shortage product in at least one of the first process and the second process.

[0180] [Aspect 13] The manufacturing planning system according to any one of Aspects 1 to 12, wherein the arithmetic circuit determines an excess product of the plurality of different products, the predicted number of which exceeds the target number, as a candidate for postponing production of the excess product in the second process, rather than the shortage product, when the period is shorter than the manufacturing lead time.

[0181] [Aspect 14] The manufacturing planning system according to any one of Aspects 1 to 13, wherein the second change plan includes selecting, as the second process, from two or more processes among the plurality of processes that are executed after the first process, a process whose time from the start of the process to the completion of the missing product is equal to or less than the remaining time.

[0182] [Aspect 15] A manufacturing planning method executed by an arithmetic circuit that can access data on a manufacturing plan for manufacturing a plurality of different products by a manufacturing facility that executes a plurality of processes, and which comprises: for a shortage product among the plurality of different products for which the predicted number of finished products on a due date is less than a target number, if the remaining time until the due date is equal to or greater than a manufacturing lead time, outputting a first modification proposal to modify the manufacturing plan to increase the number of shortage products to be manufactured in a first process that is executed first among the plurality of processes; and if the remaining time is less than the manufacturing lead time, outputting a second modification proposal to modify the manufacturing plan to prioritize the manufacturing of the shortage product in a second process that is executed after the first process among the plurality of processes.

[0183] [Aspect 16] A program for causing the arithmetic circuit to execute the manufacturing planning method of aspect 15.

[0184] Aspects 2 to 14 are optional elements and are not essential. Aspects 2 to 14 can be appropriately combined with Aspect 15.

[0185] The present disclosure is applicable to a manufacturing planning system, a manufacturing planning method, and a program for manufacturing a plurality of different products in a manufacturing facility that performs a plurality of processes.

[0186] 2 Manufacturing facility 20 Equipment 21-1 to 21-4 Equipment (first equipment) 22-1 to 22-4 Equipment (second equipment) 23-1, 23-2 Equipment (second equipment) 4 Manufacturing planning system 45 Arithmetic circuit D1 Manufacturing plan D2 Manufacturing lead time prediction model D21 Manufacturing time prediction model D22 Residence time prediction model

Claims

1. A manufacturing planning system comprising an arithmetic circuit capable of accessing manufacturing plan data for manufacturing a plurality of different products by a manufacturing facility performing a plurality of processes, wherein the arithmetic circuit outputs, for a shortage product among the plurality of different products whose predicted number of finished products on a due date is less than a target number, a first modification proposal to modify the manufacturing plan to increase the number of the shortage product to be manufactured in a first process among the plurality of processes that is executed first, when the remaining time until the due date is equal to or greater than a manufacturing lead time, and outputs a second modification proposal to modify the manufacturing plan to prioritize the manufacture of the shortage product in a second process among the plurality of processes that is executed after the first process, when the remaining time is less than the manufacturing lead time.

2. The manufacturing planning system of claim 1, wherein the manufacturing facility includes one or more first pieces of equipment that perform the first process, the manufacturing plan includes an input plan indicating a schedule for the production of the plurality of different products at the one or more first pieces of equipment, and the first change proposal includes increasing the lot of the shortage product by a predetermined number in the input plan.

3. The manufacturing planning system of claim 2, wherein the predetermined number is determined based on a number per lot of the shortage product and a difference between the forecasted number and the target number of the shortage product.

4. The manufacturing planning system of claim 2 or 3, wherein the first change proposal includes changing a lot of an excess product in the input plan to a lot of the shortage product, and the excess product is a product among the plurality of different products whose predicted quantity exceeds the target quantity.

5. The manufacturing planning system of claim 1, wherein the manufacturing facility includes one or more second equipment that performs the second process, the manufacturing plan includes a queue for the one or more second equipment, and the second change proposal includes adding the lot of the shortage product to the head of the queue for the one or more second equipment.

6. The manufacturing planning system of claim 5, wherein the second change proposal includes adding the lot of the shortage product to the head of a queue of the one or more second facilities that contains a lot of a product different from the shortage product among the plurality of different products.

7. The manufacturing planning system of claim 5, wherein the second change proposal includes adding the lot of the shortage product to the head of a queue of the one or more second facilities that contains a lot of the excess product, the excess product being a product among the plurality of different products whose forecasted quantity exceeds the target quantity.

8. The manufacturing planning system of claim 7, wherein, when there are multiple queues containing the lot of the excess product, the second modification proposal includes adding the lot of the shortage product to the head of a queue among the multiple queues that has the largest total number of lots of the excess product.

9. The manufacturing planning system of claim 1, wherein the computing circuitry detects the shortage product from among the plurality of different products based on a comparison of the forecast quantity and the target quantity for each of the plurality of different products.

10. The manufacturing planning system of claim 9, wherein the calculation circuit determines the predicted number of the plurality of different products based on the manufacturing plan, and the predicted number is given by the sum of the number of finished products already obtained, the predicted number of finished products on the due date based on the number of raw materials for the first process, and the predicted number of finished products on the due date based on the number of work-in-progress for processes other than the first process among the plurality of processes.

11. The manufacturing planning system of claim 1, wherein the calculation circuit calculates the manufacturing lead time of the shortage product using a manufacturing lead time prediction model, the manufacturing lead time prediction model including a manufacturing time prediction model that calculates the manufacturing time for each of the plurality of processes and a flow time prediction model that calculates the flow time between each of the plurality of processes, and the manufacturing lead time of the shortage product is determined based on the manufacturing time output from the manufacturing time prediction model for the shortage product and the flow time output from the flow time prediction model for the shortage product.

12. The manufacturing planning system of claim 1, wherein, when the period for an excess product among the plurality of different products, whose predicted number exceeds the target number, is equal to or longer than the manufacturing lead time, the calculation circuit selects the excess product as a candidate for postponed production in at least one of the first process and the second process, rather than the shortage product.

13. The manufacturing planning system of claim 1, wherein the calculation circuit determines, for an excess product among the plurality of different products whose predicted number exceeds the target number, that product as a candidate for postponed production in the second process compared to the shortage product when the period is shorter than the manufacturing lead time.

14. The manufacturing planning system of claim 1, wherein the second change proposal includes selecting, as the second process, from two or more processes among the plurality of processes that are executed after the first process, a process whose time from the start of the process to the completion of the missing product is equal to or less than the remaining time.

15. A manufacturing planning method, which is executed by an arithmetic circuit that can access manufacturing plan data for manufacturing a plurality of different products by a manufacturing facility performing a plurality of processes, and which outputs, for a shortage product among the plurality of different products whose predicted number of finished products on a due date is less than a target number, a first modification proposal to modify the manufacturing plan to increase the number of the shortage product to be manufactured in a first process that is executed first among the plurality of processes, when the remaining time until the due date is equal to or greater than a manufacturing lead time, and outputs a second modification proposal to modify the manufacturing plan to prioritize the manufacture of the shortage product in a second process that is executed after the first process among the plurality of processes, when the remaining time is less than the manufacturing lead time.

16. A program for causing the arithmetic circuit to execute the manufacturing planning method of claim 15.

Images