Injection molding process bill of materials optimization method

Abstract

The application provides an injection molding process material list optimization method, comprising the following steps: S1. obtaining attribute information of a to-be-produced injection molding product, wherein the attribute information comprises a product model, structure, size and material, of course, in actual application, more categories can be set in the attribute information, and details are not described herein; S2. matching the attribute information of the to-be-produced injection molding product with historical product information in a database to find out a theoretical amount and an actual amount of material consumption of a target historical product consistent with the attribute information of the to-be-produced injection molding product; S3. determining a material consumption deviation rate of the historical product, and then determining a mean value of the material consumption deviation rate; S4. determining a material order quantity and a nozzle material suggestion quantity according to the mean value of the material consumption deviation rate; and S5. updating a reference single-product reference consumption amount in a material list of the to-be-produced injection molding product according to the material order quantity and the nozzle material suggestion quantity determined in step S4.

Description

Technical Field

[0001] This invention relates to a method for optimizing injection molding processes, and more particularly to a method for optimizing the bill of materials (BOM) for injection molding processes. Background Technology

[0002] In injection molding, the bill of materials (BOM) for a product (including material number, specifications, quantity, etc.) is the core data guiding material requisition for production, cost accounting, and inventory management. It is generally determined through a static process. In existing technology, the material requirements for a single product are estimated based on the specifications and dimensions of the injection molded product, and then the material requisition quantity is determined based on the production volume of the product. Of course, the available surplus material status of the line-side warehouse is also taken into account in this process (i.e., the actual demand is calculated by subtracting the available surplus material in the warehouse).

[0003] However, the bill of materials generated above cannot accurately guide actual injection molding production. It often results in a large discrepancy between the materials issued and the actual materials required, which in turn affects the production process. This is because in injection molding production, the influence of process parameters such as temperature, pressure, and holding pressure often leads to a deviation between the actual usage and the theoretical value, that is, the actual usage is greater than the material requisition. As a result, the current approach is to increase the actual demand based on experience, which in turn causes problems such as material accumulation in the line-side warehouse and increased production cost pressure.

[0004] Therefore, in order to solve the above-mentioned technical problems, it is urgent to propose a new technical approach. Summary of the Invention

[0005] In view of this, the purpose of this invention is to provide a method for optimizing the bill of materials (BOM) for injection molding processes. This method constructs the material requirement coefficient for the injection-molded product to be produced by using the material usage deviation rate of historical products. Then, the final material requisition quantity is determined by the planned output of the product to be produced and the theoretical consumption per unit. This ensures that the material requisition quantity in the BOM has a small deviation from the actual material usage of the injection-molded product to be produced. This method can not only meet the actual production needs, but also reduce the possibility of increased production costs caused by material backlog in the line-side warehouse and reduce the impact of material backlog on production. It can accurately guide injection molding production and its warehouse management.

[0006] This invention provides a method for optimizing the bill of materials (BOM) for injection molding processes, comprising the following steps:

[0007] S1. The attribute information of the injection-molded product to be produced, including the product's model, structure, size, and material;

[0008] S2. Match the attribute information of the injection-molded product to the historical product information in the database to find the theoretical and actual material consumption of the target historical product that matches the attribute information of the injection-molded product to be produced;

[0009] S3. Determine the material consumption deviation rate of historical products, and then determine the average material consumption deviation rate;

[0010] S4. Determine the material requisition quantity and the recommended quantity of sprue material based on the average material consumption deviation rate;

[0011] S5. Update the baseline consumption per unit in the bill of materials for the injection molded products to be produced according to the material requisition quantity and the recommended quantity of sprue material determined in step S4.

[0012] Furthermore, step S3 specifically includes:

[0013] Calculate the material consumption deviation rate:

[0014] ;

[0015] in: This represents the material consumption deviation for batch t of historical products. This represents the theoretical material consumption for batch t of historical products. This represents the actual material consumption of the t-th batch of historical products;

[0016] Calculate the average material consumption deviation rate:

[0017] ;

[0018] in: This represents the average material consumption deviation rate. This represents the exponentially weighted average of the deviation in material consumption rate for batch t-1. This represents the smoothing factor.

[0019] Furthermore, in step S4, determining the material requisition quantity based on the average material consumption deviation rate specifically includes:

[0020] The material consumption coefficient of the injection molded product to be produced is determined by the average historical product material consumption deviation rate.

[0021] Construct a material requisition quantity model:

[0022] ;

[0023] in: This represents the current material requisition quantity for the injection-molded products awaiting production, where Q represents the planned output of the injection-molded products awaiting production. Indicates the material consumption coefficient. This indicates the baseline consumption for a single injection-molded product awaiting production. This indicates the amount of remaining material available in the line-side warehouse.

[0024] Furthermore, the material consumption coefficient Specifically:

[0025] ;

[0026] Where: c represents a constant coefficient less than 1, Indicates seasonal influencing factors. The values ​​are 0 and 1. When the production season of the historical product is the same as the production season of the current injection molded product, the value is 0; otherwise, the value is 1. This indicates the factors affecting equipment aging.

[0027] Furthermore, in step S4, the recommended amount of sprue material is determined using the following method:

[0028] ;

[0029] in: This indicates the recommended amount of sprue material for the injection-molded product to be produced. This indicates the historical best sprue recovery rate. This indicates the maximum allowable proportion of sprue material to be added.

[0030] Furthermore, in step S2, the determination of the target historical product specifically includes:

[0031] The attribute information of the injection molded products to be produced is compared one by one with the attribute information of historical products in the database, and historical products with consistent attribute information are selected as candidate historical products.

[0032] Determine if the number of production batches in the candidate historical products is greater than or equal to 2. If not, remove the current candidate historical products. If so, determine if the average yield rate of the historical products is greater than a set threshold. If not, extract the current historical products. If so, select the historical product with the highest average yield rate as the target historical product.

[0033] Furthermore, in step S5, the baseline consumption per unit in the bill of materials for the injection-molded products to be produced is updated, specifically including:

[0034] Determine the material consumption deviation rate for each batch of injection-molded products during the production process;

[0035] If the material deviation efficiency of N consecutive batches is less than the set threshold, then update the baseline consumption of a single injection-molded product in the bill of materials:

[0036] ;

[0037] .

[0038] The beneficial effects of this invention are as follows: By constructing the material demand coefficient of the injection-molded product to be produced based on the material deviation rate of historical products, the final material requisition quantity is determined by the planned output of the product to be produced and the theoretical consumption of a single product. This results in a smaller deviation between the material requisition quantity in the bill of materials and the actual material consumption of the injection-molded product to be produced. This not only meets the actual production needs but also reduces the possibility of increased production costs caused by material backlog in the line-side warehouse and reduces the impact of material backlog on production. It can accurately guide injection molding production and its warehousing management. Attached Figure Description

[0039] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0040] Figure 1 This is a flowchart of the present invention. Detailed Implementation

[0041] The present invention will be further described in detail below:

[0042] This invention provides a method for optimizing the bill of materials (BOM) for injection molding processes, comprising the following steps:

[0043] S1. The attribute information of the injection-molded product to be produced, including the product's model, structure, size, and material. Of course, in practice, more directories can be set for the attribute information, which will not be elaborated here.

[0044] S2. Match the attribute information of the injection-molded product to the historical product information in the database to find the theoretical and actual material consumption of the target historical product that matches the attribute information of the injection-molded product to be produced;

[0045] S3. Determine the material consumption deviation rate of historical products, and then determine the average material consumption deviation rate;

[0046] S4. Determine the material requisition quantity and the recommended quantity of sprue material based on the average material consumption deviation rate;

[0047] S5. Update the baseline consumption per unit in the bill of materials for the injection-molded product to be produced according to the material requisition quantity and the suggested quantity of sprue material determined in step S4. Using the above method, the material demand coefficient for the injection-molded product to be produced is constructed based on the material usage deviation rate of historical products. Then, the final material requisition quantity is determined by the planned output of the product to be produced and the theoretical consumption per unit. This ensures that the material requisition quantity in the bill of materials has a small deviation from the actual material usage of the injection-molded product to be produced. This not only meets actual production needs but also reduces the possibility of increased production costs caused by material backlog in the line-side warehouse and minimizes the impact of material backlog on production. It accurately guides injection molding production and its warehousing management.

[0048] In this embodiment, step S3 specifically includes:

[0049] Calculate the material consumption deviation rate:

[0050] (1);

[0051] in: This represents the material consumption deviation for batch t of historical products. This represents the theoretical material consumption for batch t of historical products. This represents the actual material consumption of the t-th batch of historical products;

[0052] Calculate the average material consumption deviation rate:

[0053] (2);

[0054] in: This represents the average material consumption deviation rate. This represents the exponentially weighted average of the deviation in material consumption rate for batch t-1. The smoothing factor is used. In the above process, the exponential weighted average method is used to calculate the mean of the material consumption deviation rate, so that the obtained parameters are more in line with the actual working conditions. This is because, in injection molding production, the production equipment will age over time rather than in a static process. Therefore, in the above process, more attention is paid to the data most recent to the current time when calculating the average, while the importance of data far from the current time is reduced. The data most recent to the current time can better reflect the impact of the cumulative effect of equipment aging, thus making the assessment of material demand more accurate.

[0055] In this embodiment, step S4, determining the material requisition quantity based on the average material consumption deviation rate, specifically includes:

[0056] The material consumption coefficient of the injection molded product to be produced is determined by the average historical product material consumption deviation rate.

[0057] Construct a material requisition quantity model:

[0058] (3);

[0059] in: Q represents the current material requirement for injection-molded products awaiting production, and Q represents the planned output of those products. Indicates the material consumption coefficient. This indicates the baseline consumption for a single injection-molded product awaiting production. This indicates the amount of remaining material available in the line-side warehouse.

[0060] The material consumption coefficient Specifically:

[0061] (4);

[0062] Where: c represents a constant coefficient less than 1, This represents the seasonal influence factor; its value varies depending on the season and is determined through actual experiments. The values ​​are 0 and 1. When the production season of the historical product is the same as the production season of the current injection molded product, the value is 0; otherwise, the value is 1. This represents the aging impact factor of equipment (since equipment aging is caused by multiple factors, aging experiments are generally conducted on equipment based on different materials to obtain the corresponding aging impact coefficient). In the above, the consumption coefficient... Two factors were considered in the determination process: seasonal factors and equipment aging factors. The text considers the impact of equipment aging, but only at a specific point in time within historical products. There's a time interval between the end of historical production and the current time, during which the equipment is also aging, thus causing an impact. Seasonal factors affect temperature, pressure holding, and cooling, thereby influencing material consumption. Therefore, within the same season (meaning the average temperature difference is less than a set threshold; even if the average temperature difference within the same season is greater than the set threshold), then... If the value of is still 1, then seasonal factors are not considered; however, when the seasons are different, the seasonal impact is taken into account. Through the above methods, the deviation between the material quantity in the bill of materials and the actual material quantity required can be effectively reduced, ensuring that the bill of materials can accurately guide actual production and warehousing management.

[0063] In this embodiment, in step S4, the recommended amount of sprue material is determined by the following method:

[0064] (5);

[0065] in: This indicates the recommended amount of sprue material for the injection-molded product to be produced. This indicates the historical best sprue recovery rate (the best sprue refers to the sprue whose quality differs the least from the original material). This indicates the maximum allowable proportion of sprue material to be added. In the bill of materials, the recommended amount of sprue material is also one of the parameters. Based on the above, it is possible to make the material requisition quantity in the bill of materials match the actual consumption quantity.

[0066] In this embodiment, step S2, determining the target historical product specifically includes:

[0067] The attribute information of the injection molded products to be produced is compared one by one with the attribute information of historical products in the database, and historical products with consistent attribute information are selected as candidate historical products.

[0068] If the number of production batches in the candidate historical products is greater than or equal to 2, the current candidate historical products are removed. If they are, the average yield rate of the historical products is determined to be greater than a set threshold. If not, the current historical products are extracted. If they are, the historical products with the highest average yield rate are selected as the target historical products. Through the above, the accuracy of the material quantity in the bill of materials can be ensured.

[0069] In this embodiment, step S5, updating the baseline consumption of a single product in the bill of materials for the injection-molded product to be produced, specifically includes:

[0070] Determine the material consumption deviation rate for each batch of the injection-molded product to be produced (at this point, the injection-molded product to be produced becomes an actual product being produced; for the sake of terminology consistency, this name will still be used) during the production process.

[0071] If the material deviation efficiency of N consecutive batches is less than the set threshold, then update the baseline consumption of a single injection-molded product in the bill of materials:

[0072] (7);

[0073] (8). In formula (3), the baseline consumption is... This is an estimated theoretical value. In each production run, a fixed baseline value is used, which increases the deviation in subsequent calculations. However, through this embodiment, the baseline consumption can be updated. In formulas (7) and (8), it is also necessary to calculate the material consumption coefficients for each batch of the injection-molded products to be produced. The material consumption coefficient The calculation formula is the same as formula (4). At this time, the seasonal coefficient term is set to 1, which is calculated based on the material deviation rate of each batch of injection molded products in the current production.

[0074] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method for optimizing the bill of materials (BOM) for injection molding processes, characterized in that: Includes the following steps: S1. The attribute information of the injection-molded product to be produced, including the product's model, structure, size, and material; S2. Match the attribute information of the injection-molded product to the historical product information in the database to find the theoretical and actual material consumption of the target historical product that matches the attribute information of the injection-molded product to be produced; S3. Determine the material consumption deviation rate of historical products, and then determine the average material consumption deviation rate; S4. Determine the material requisition quantity and the recommended quantity of sprue material based on the average material consumption deviation rate; S5. Update the standard consumption per unit in the bill of materials for the injection molded products to be produced according to the material requisition quantity and the recommended quantity of sprue material determined in step S4.

2. The method for optimizing the bill of materials for injection molding process according to claim 1, characterized in that: Step S3 specifically includes: Calculate the material consumption deviation rate: ； in: This represents the material consumption deviation for batch t of historical products. This represents the theoretical material consumption for batch t of historical products. This represents the actual material consumption of the t-th batch of historical products; Calculate the average material consumption deviation rate: ； in: This represents the average material consumption deviation rate. This represents the exponentially weighted average of the deviation in material consumption rate for batch t-1. This represents the smoothing factor.

3. The method for optimizing the bill of materials for injection molding process according to claim 2, characterized in that: In step S4, determining the material requisition quantity based on the average material consumption deviation rate specifically includes: The material consumption coefficient of the injection molded product to be produced is determined by the average historical material consumption deviation rate. Construct a material requisition quantity model: ； in: This represents the current material requisition quantity for the injection-molded products awaiting production, where Q represents the planned output of the injection-molded products awaiting production. Indicates the material consumption coefficient. This indicates the baseline consumption for a single injection-molded product awaiting production. This indicates the amount of remaining material available in the line-side warehouse.

4. The method for optimizing the bill of materials for injection molding process according to claim 3, characterized in that: The material consumption coefficient Specifically: ； Where: c represents a constant coefficient less than 1, Indicates seasonal influencing factors. The values ​​are 0 and 1. When the production season of the historical product is the same as the production season of the current injection molded product, the value is 0; otherwise, the value is 1. This indicates the factors affecting equipment aging.

5. The method for optimizing the bill of materials for injection molding process according to claim 3, characterized in that: In step S4, the recommended amount of sprue is determined using the following method: ； in: This indicates the recommended amount of sprue material for the injection-molded product to be produced. This indicates the historical best sprue recovery rate. This indicates the maximum allowable proportion of sprue material to be added.

6. The method for optimizing the bill of materials for injection molding process according to claim 1, characterized in that: In step S2, the determination of the target historical product specifically includes: The attribute information of the injection molded products to be produced is compared one by one with the attribute information of historical products in the database, and historical products with consistent attribute information are selected as candidate historical products. Determine if the number of production batches in the candidate historical products is greater than or equal to 2. If not, remove the current candidate historical products. If so, determine if the average yield rate of the historical products is greater than a set threshold. If not, extract the current historical products. If so, select the historical product with the highest average yield rate as the target historical product.

7. The method for optimizing the bill of materials for injection molding process according to claim 4, characterized in that: In step S5, the baseline consumption per unit in the bill of materials for the injection-molded products to be produced is updated, specifically including: Determine the material consumption deviation rate for each batch of injection-molded products during the production process; If the material deviation efficiency of N consecutive batches is less than the set threshold, then update the baseline consumption of a single injection-molded product in the bill of materials: ； 。

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