Ship block construction cycle planning method

Abstract

The invention provides a ship block construction period planning method. The method comprises the following steps: determining a cycle period of ship construction; obtaining a demand node of each block in the target block family in the ship construction process; determining a construction period corresponding to each block in the target block family; calculating an inventory period of each block; calculating a vacancy period of each block; and determining the construction rhythm of the target block family, and then combining the construction rhythm with the cycle period, the inventory period and the vacancy period of each block in the target block family to make a ship block construction period planning table for reflecting the composition structure of the cycle period of each block in the target block family. According to the technical scheme, the ship block construction period planning table is made by establishing the relation between the construction rhythm and the vacancy period and the inventory period, a visual tool for ship construction period planning can be provided for technicians, and the technicians can flexibly select the construction rhythm and manage and monitor the construction progress.

Description

Technical Field

[0001] This application relates to the field of shipbuilding, and more specifically, to a method for planning the construction cycle of ship sections. Background Technology

[0002] The modular construction method plays a crucial role in modern shipbuilding, serving as a crucial link between the initial and subsequent stages. Before a ship enters the dry dock or is placed on the slipway, it typically undergoes this phase. In this method, the ship is broken down into multiple relatively independent sections (including cargo hold sections, engine room sections, bow and stern sections, and superstructure sections). Each section can be constructed independently in different sites or workshops. During construction, each section completes most of the structural, outfitting, and painting work. Once a certain engineering condition is reached, these sections are then hoisted onto the dry dock or slipway in a predetermined sequence for assembly. By breaking down the ship into multiple large sections for separate construction, the modular construction method offers advantages such as parallel operations, optimized resource utilization, improved construction quality, and reduced construction costs and risks. It is widely used in complex large-scale shipbuilding tasks, such as cargo ships, tankers, container ships, and passenger ships.

[0003] However, traditional modular construction methods often focus on construction techniques and processes, neglecting the crucial role of modular cycle and inventory cycles in the construction process. In actual construction, the demand for modular sections in subsequent docks or slipways is affected by various factors, such as holiday schedules, weather conditions, and design changes, resulting in an irregular and unstable state with significant uncertainty. Traditional construction methods struggle to adapt to this uncertainty and cannot make corresponding adjustments, easily leading to material concentration in certain time periods and causing significant supply-demand mismatches. This imbalanced production model easily leads to inventory backlogs or excessively long vacancy periods, severely impacting production efficiency, construction costs, and delivery cycles. Summary of the Invention

[0004] The purpose of this application is to provide a method for planning the construction cycle of ship sections. By establishing the relationship between the construction cycle, the idle period, and the inventory period, a ship section construction cycle planning table is created. This provides technicians with a visual tool for ship construction cycle planning, enabling them to flexibly select the most suitable construction cycle according to actual needs and conveniently manage and monitor the construction progress.

[0005] This application provides a method for planning the construction cycle of a ship block, including the following steps:

[0006] S1. Determine the cycle of ship construction based on the ship production plan;

[0007] S2. Based on the engineering network diagram or process flow diagram of the dock or slipway, obtain the demand nodes of each section in the target section family in the shipbuilding process.

[0008] S3. Based on the engineering network diagram or process flow diagram of the dock or slipway, determine the corresponding construction period of each section in the target section family;

[0009] S4. Calculate the inventory cycle of each segment by combining the demand nodes and construction cycle of each segment in the target segment family;

[0010] S5. Calculate the vacancy period of each section by combining the shipbuilding cycle and the inventory cycle and construction cycle of each section in the target section family.

[0011] S6. Combining the shipbuilding cycle and the number of sections in the target section family, determine the construction rhythm of the target section family. Then, combine the construction rhythm with the cycle, inventory cycle, and vacancy cycle of each section in the target section family to create a ship section construction cycle planning table, which reflects the composition structure of the cycle of each section in the target section family.

[0012] In one feasible approach, the cycle of shipbuilding is calculated using the following formula: P t =T / B; where, P t For the shipbuilding cycle, the total annual production time in the production plan is T, and the number of batches launched annually is B.

[0013] In one feasible approach, the total inventory cycle is calculated using the following formula: P w =P r -P c The demand cycle for ship sections is defined as the period from the ship section construction cycle P. c The time period from the starting point to the demand node, P r The demand cycle for the entire segment; P w For the total inventory cycle, P r For the total demand period, P c The construction period for the entire section.

[0014] In one feasible scenario, the total inventory cycle P is... w Satisfy the following equation: P w ≥0.

[0015] In one feasible approach, the idle period of the total segment is calculated using the following formula: P u =P t -P c -P w Among them, P u For the total idle period of the segment, Pt The cycle of ship construction, P c For the construction period of the entire section, P w This refers to the inventory cycle of the entire segment.

[0016] In one feasible scheme, the total idle period P of the segment u Satisfy the following equation: P u ≥0.

[0017] In a feasible scheme, the relationship between the shipbuilding cycle, the construction pace, and the number of sections in the target section family satisfies the following equation: P t ≥R×Z; where R is the construction cycle of the target total segment family, and Z is the number of total segments in the target total segment family.

[0018] In one feasible embodiment, step S6 includes the following steps:

[0019] S601. Calculate the initial construction cycle R of the target total segment family according to the following formula: R = P t / Z; where R is the construction cycle time of the target section family, and Z is the number of sections in the target section family; then, a ship section construction cycle planning table is created by combining the cycle time, inventory time, and vacancy time of each section in the target section family. If the ship section construction cycle planning table simultaneously satisfies P w ≥0 and P u If the value is ≥0, then it is marked as a feasible planning table;

[0020] S602. Reduce the construction cycle R by one basic time unit, and then correspondingly create a ship section construction cycle planning table. If the ship section construction cycle planning table simultaneously satisfies P... w ≥0 and P u If the value is ≥0, then it is marked as a feasible planning table;

[0021] S603. Repeat step S602 until the construction cycle R is reduced to one basic time unit, and finally one or more feasible plans are formed. Then select the feasible plan with the smallest construction cycle R as the final ship section construction cycle plan.

[0022] In a feasible approach, the basic unit of time is the day.

[0023] In one feasible approach, multiple constraints are considered during the ship section construction cycle planning process. These constraints include the number of personnel, the number of cranes, the amount of materials, the number of tools and fixtures, and the continuity of work processes. Each constraint corresponds to a preset threshold, and in the final ship section construction cycle planning table, each constraint element does not exceed its respective preset threshold.

[0024] Compared with the prior art, the beneficial effects of this application include at least the following:

[0025] This application provides a method for planning the construction cycle of ship sections. It calculates the cycle of a target family of sections and decomposes the cycle into the section's cycle cycle, inventory cycle, demand nodes, and vacancy cycle. It establishes the relationship between the construction takt time and the vacancy and inventory cycles, and accordingly creates a ship section construction cycle planning table. This table visually reflects the distribution of the cycle cycles of each section, conveniently and intuitively displaying the composition of each section's cycle cycle. This provides technicians with a visual tool for ship construction cycle planning, allowing them to flexibly select the most suitable construction takt time based on actual needs and easily manage and monitor the construction progress. The ship construction cycle planning table also helps technicians rationally plan inventory. Therefore, when faced with raw material quality problems or unexpected situations during construction, technicians can take timely measures to repair or replace parts, thereby ensuring the construction quality of the sections and reducing rework and repair costs caused by quality issues. In addition, by setting reasonable inventory cycles and vacancy cycles, it is possible to effectively avoid the capital backlog and increased warehousing costs caused by excessive inventory, while also preventing additional costs caused by emergency procurement due to material shortages, thereby effectively controlling shipbuilding costs.

[0026] Furthermore, technicians can create separate ship section construction cycle plans for multiple different construction cycles. Under the premise of ensuring that each ship section can be delivered on time and that the construction quality is up to standard, the shortest construction cycle can be selected to minimize the ship section construction cycle and ensure that the section construction process can be carried out continuously and efficiently. Attached Figure Description

[0027] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 This is a flowchart illustrating a ship block construction cycle planning method according to an embodiment of this application;

[0029] Figure 2 A schematic diagram of the engineering network of a dock or slipway;

[0030] Figure 3 A process flow diagram for a specific ship section;

[0031] Figure 4This is the first schematic diagram of a ship section construction cycle planning table;

[0032] Figure 5 This is a second schematic diagram of the ship section construction cycle planning table. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0034] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0035] like Figure 1 As shown, this application provides a method for planning the construction cycle of a ship block, including the following steps:

[0036] S1. Determine the cycle of ship construction based on the ship production plan.

[0037] S2. Based on the engineering network diagram or process flow diagram of the dock or slipway, obtain the demand nodes of each section in the target section family in the shipbuilding process. Specifically, the sections for shipbuilding can be classified according to the quantity, type, region, process flow, etc., to form multiple section families. Each section family can consist of one or more sections. For example, the bottom section family can include 5 sections.

[0038] S3. Based on the engineering network diagram or process flow diagram of the dock or slipway, determine the corresponding construction period of each section in the target section family.

[0039] S4. Calculate the inventory cycle of each segment by combining the demand nodes and construction cycle of each segment in the target segment family.

[0040] S5. Calculate the vacancy period of each section by combining the shipbuilding cycle and the inventory and construction cycles of each section in the target section family.

[0041] S6. Combining the shipbuilding cycle and the number of sections in the target section family, determine the construction rhythm of the target section family. Then, combine the construction rhythm with the cycle, inventory cycle, and vacancy cycle of each section in the target section family to create a ship section construction cycle planning table, which reflects the composition structure of the cycle of each section in the target section family.

[0042] Specifically, in step S1, P can be used. t =T / B is used to calculate the cycle of shipbuilding. Where, P t For the shipbuilding cycle, the total annual production time in the production plan is T, and the number of batches launched annually is B. For example, in the production plan, the total annual production time T is 360 days, and the number of batches launched annually is 8, then the cycle period P is... t =360 / 8=45 (days), which means that for a ship under construction, the entire process from the start of construction to loading of each section must be controlled within 45 days. Otherwise, it may cause the construction of other ships to be delayed, affecting the overall production schedule.

[0043] For steps S2-S4, the inventory cycle of the total segment can be calculated using the following formula: P w =P r -P c The demand cycle for ship sections is defined as the period from the ship section construction cycle P. c The time period from the starting point to the demand node, P r This is the demand cycle for the entire segment. In addition, P... w For the total inventory cycle, P r For the total demand period, P c This refers to the construction cycle of the ship sections. The demand milestones refer to the specific time points at which a ship section needs to be hoisted onto the dock or slipway for installation. The demand milestones for each section can be obtained through the dock or slipway's engineering network diagram or process flow diagram, such as... Figure 2 As shown. It is important to note that the timeframes for the requirements of each segment are fixed and cannot be changed.

[0044] Construction period P c This refers to the actual time required to complete one section within a group of sections, and its value depends on the current actual construction capacity. In actual construction, the construction period of each section is determined according to the ship's engineering network diagram or process flow diagram; that is, for a given section, its construction period P is... c Because the value is fixed, compression is not possible. For example, the construction period P of section 31Z. c The process takes 15 days, and the corresponding process flow diagram is as follows: Figure 2As shown, the engineering network diagram or process flow diagram must clearly define the transition points, main lines, and auxiliary lines between each process, and must include all structural, outfitting, painting, testing, and other operations during the construction of this section.

[0045] Inventory cycle P w This refers to the period during which the main structure of a section has been completed, but it has not yet entered the subsequent assembly process and remains on the jig, waiting. This is within the inventory cycle P. w Inside, the entire section is in a state of idleness, but some installation work can still be carried out (such as outfitting component installation), therefore the inventory cycle P w Excessive length will occupy the rack space, resulting in wasted production capacity and increased costs. Inventory cycle P for any total segment. w All should satisfy P w ≥0, i.e., P r -P c ≥0, meaning the entire section must be completed before the demand node; otherwise, the section cannot be delivered to the subsequent stages on time, affecting the overall construction progress. For a family of sections, the inventory cycle P of each section... w Calculate them separately.

[0046] In step S5, the idle period of the total segment can be calculated using the following formula: P u =P t -P c -P w Among them, P u For the total idle period of the segment, P t The cycle of ship construction, P c For the construction period of the entire section, P w The total inventory cycle. Idle cycle P. u This refers to the idle time from the completion of all construction and installation work on a section and its hoisting away from the construction jig until the start of construction on the next section. During this period, the construction jig is not under any work and is in a vacant state ready to be assigned new tasks. The vacancy period P of any section is... u All should satisfy P u ≥0, which means P t ≥P c +P w or P t ≥P r This is because only when the construction process of each section does not exceed the cycle can the overall shipbuilding process be ensured to be on schedule, thereby ensuring the smooth completion of the annual production plan. For a family of sections, the idle period P of each section... u Calculate them separately.

[0047] The relationship between the shipbuilding cycle, the construction pace, and the number of sections in the target section family satisfies Pt ≥R×Z. Where R is the construction cycle time of the target total segment family, and Z is the total number of segments in the target total segment family. Cycle period P t To determine a specific value, it is based on the actual annual production target. For a given target family of segments, the total number of segments Z is also a fixed value. Because P t =P c +P w +P u Therefore, the above formula can be written as R×Z≤P c +P w +P u Wherein, the construction cycle R is a random variable, and the inventory period P is a random variable. w and idle period P u Using the building cycle R as the dependent variable, an equilibrium calculation model is established. By changing the value of the building cycle R, different inventory cycles P can be obtained. w and the idle period P u By organizing the construction cycle P of each segment in the target segment family c Inventory cycle P w Idle period P u And based on demand nodes, a ship section construction cycle planning table can be created, such as... Figure 4 As shown, the target segment family can include 5 segments, each segment corresponding to a row in the ship segment construction cycle planning table; each cell represents one day, and the time difference between the start points of two adjacent rows is the construction cycle R; the cycle period P of each segment is... t According to the chronological order, it can be divided into construction cycles P. c Inventory cycle P w Demand nodes and idle periods P u Different colors are used to mark each section. The ship section construction cycle planning table can intuitively reflect the progress of each section in the target section family. Technical personnel can quickly judge whether the current time plan is reasonable, thereby effectively improving the effectiveness and efficiency of ship section construction cycle planning.

[0048] In actual production, ensuring that the main section can be delivered normally at the demand node (i.e., P) w Under the premise of ≥0), the principle of minimizing inventory cycle P should be followed. w And increase the idle period P u The principle of selecting an appropriate construction cycle R is based on the principle of idling period P. u In this process, the construction space can be used for the construction of other sections, maximizing equipment capacity utilization while reducing inventory cycle P. w This would occupy a construction space. Therefore, in the actual application of the ship block construction cycle planning method, step S6 may include the following specific steps:

[0049] S601, According to R=P t / Z, calculate the initial construction cycle R of the target section family. Where R is the construction cycle of the target section family, and Z is the number of sections in the target section family; then, combine the cycle period, inventory period, and vacancy period of each section in the target section family to create a ship section construction cycle planning table. If the ship section construction cycle planning table simultaneously satisfies P... w ≥0 and P u If the value is ≥0, it is marked as a feasible planning table, meaning that the ship construction can be completed normally and delivered on time according to the ship section construction cycle planning table.

[0050] For example, the cycle P of shipbuilding is calculated based on the production plan. t = 45 (days), and the target total segment family includes 5 total segments, so according to step S601, the initial construction cycle R = 45 / 5 = 9 (days). Figure 4 The table showing the ship section construction cycle planning is presented when R = 9 (days). Specifically, the construction cycle P for sections 1 to 5 is shown. c All are 15 days, inventory cycle P w The idle periods are 24 days, 16 days, 3 days, 0 days, and 1 day, respectively, with an idle period P. u The durations are 5 days, 13 days, 26 days, 29 days, and 28 days, respectively. As can be seen from the graph, all segments satisfy P. w ≥0 and P u The requirement of ≥0 means that the ship section construction cycle plan when R = 9 (days) is a feasible plan.

[0051] S602. Reduce the construction cycle R by one basic time unit (in this embodiment, one basic time unit is one day), and then correspondingly create a ship section construction cycle planning table. If the ship section construction cycle planning table simultaneously satisfies P... w ≥0 and P u If the value is ≥0, it is marked as a feasible planning table.

[0052] S603. Repeat step S602 until the construction cycle R is reduced to one basic time unit (i.e., one day), ultimately forming one or more feasible plans. Then, select the feasible plan with the smallest construction cycle R as the final ship section construction cycle plan. For example, Figure 5 The table showing the ship section construction cycle planning for R=3 (days) is clearly a feasible planning table. (Comparison) Figure 4 and Figure 5It can be seen that, compared with R=9 (days), choosing R=3 (days) can effectively improve the utilization rate of the construction space, further shorten the overall construction time of the target block family, and help ensure the smooth progress of the ship construction process in the event of unforeseen emergencies, avoiding problems such as delivery delays.

[0053] In the process of planning the construction cycle of a ship section, several constraints can be considered, including the number of personnel, the number of cranes, the amount of materials, the quantity of tools and fixtures, and the continuity of work processes. Each constraint corresponds to a preset threshold, and in the final ship section construction cycle plan, each constraint element shall not exceed its respective preset threshold. Specifically, the personnel number factor mainly considers that the peak number of personnel per unit time should not exceed the preset threshold to avoid affecting work efficiency and increasing safety risks due to an overcrowded working environment. The crane number factor mainly considers that the peak number of cranes per unit time, whether there are conflicts, or the number of lifting operations (lifting time) should not exceed the preset threshold. The material quantity factor mainly considers that the material quantity per unit time should not exceed the preset threshold, which would lead to a peak in personnel or equipment input exceeding the preset threshold. The tool and fixture quantity factor mainly considers that the peak number of tools and fixtures per unit time should not exceed the preset threshold. The work process continuity factor mainly considers that the work process should not be interrupted due to insufficient supply of personnel, cranes, and tools and fixtures per unit time.

[0054] In summary, this application provides a method for planning the construction cycle of ship sections. It calculates the cycle of a target family of sections and decomposes the cycle into the section's cycle cycle, inventory cycle, demand nodes, and vacancy cycle. It establishes the relationship between the construction takt time and the vacancy and inventory cycles, and accordingly creates a ship section construction cycle planning table. This table visually reflects the distribution of the cycle cycles of each section, conveniently and intuitively displaying the composition of each section's cycle cycle. This provides technicians with a visual tool for ship construction cycle planning, allowing them to flexibly select the most suitable construction takt time based on actual needs and easily manage and monitor the construction progress. The ship construction cycle planning table also helps technicians rationally plan inventory. Therefore, when faced with raw material quality problems or unexpected situations during construction, technicians can take timely measures to repair or replace parts, thereby ensuring the construction quality of the sections and reducing rework and repair costs caused by quality issues. In addition, by setting reasonable inventory cycles and vacancy cycles, it is possible to effectively avoid the capital backlog and increased warehousing costs caused by excessive inventory, while also preventing additional costs caused by emergency procurement due to material shortages, thereby effectively controlling shipbuilding costs.

[0055] Furthermore, technicians can create separate ship section construction cycle plans for multiple different construction cycles. Under the premise of ensuring that each ship section can be delivered on time and that the construction quality is up to standard, the shortest construction cycle can be selected to minimize the ship section construction cycle and ensure that the section construction process can be carried out continuously and efficiently.

[0056] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A method for planning the construction cycle of a ship block, characterized in that, include: S1. Determine the cycle of ship construction based on the ship production plan; S2. Based on the engineering network diagram or process flow diagram of the dock or slipway, obtain the demand nodes of each section in the target section family in the shipbuilding process. S3. Based on the engineering network diagram or process flow diagram of the dock or slipway, determine the corresponding construction period of each section in the target section family; S4. Calculate the inventory cycle of each segment by combining the demand nodes and construction cycle of each segment in the target segment family; S5. Calculate the vacancy period of each section by combining the shipbuilding cycle and the inventory cycle and construction cycle of each section in the target section family. S6. Combining the shipbuilding cycle and the number of sections in the target section family, determine the construction rhythm of the target section family. Then, combine the construction rhythm with the cycle, inventory cycle, and vacancy cycle of each section in the target section family to create a ship section construction cycle planning table, which reflects the composition structure of the cycle of each section in the target section family.

2. The ship block construction cycle planning method according to claim 1, characterized in that, The cycle of shipbuilding is calculated using the following formula: P t =T / B; Among them, P t For the shipbuilding cycle, the total annual production time in the production plan is T, and the number of batches launched annually is B.

3. The ship block construction cycle planning method according to claim 2, characterized in that, The inventory cycle for the entire segment is calculated using the following formula: P w =P r -P c ; The demand cycle for ship sections is defined as the period from the ship section construction cycle P. c The time period from the starting point to the demand node, P r The demand cycle for the entire segment; P w For the total inventory cycle, P r For the total demand period, P c The construction period for the entire section.

4. The ship block construction cycle planning method according to claim 3, characterized in that, Total inventory cycle P w Satisfy the following formula: P w ≥0。 5. The ship block construction cycle planning method according to claim 4, characterized in that, The idle period of the total segment is calculated using the following formula: P u =P t -P c -P w ; Among them, P u For the total idle period of the segment, P t The cycle of ship construction, P c For the construction period of the entire section, P w This refers to the inventory cycle of the entire segment.

6. The ship block construction cycle planning method according to claim 5, characterized in that, Total idle period P u Satisfy the following formula: P u ≥0。 7. The ship block construction cycle planning method according to claim 6, characterized in that, The relationship between the shipbuilding cycle, the construction pace, and the number of sections in the target section family satisfies the following formula: P t ≥R×Z; Where R is the construction cycle of the target segment family, and Z is the number of segments in the target segment family.

8. The ship block construction cycle planning method according to claim 7, characterized in that, Step S6 includes: S601. Calculate the initial construction cycle R of the target total segment family according to the following formula: R=P t / Z; Where R is the construction cycle time of the target section family, and Z is the number of sections in the target section family; then, a ship section construction cycle planning table is created by combining the cycle time, inventory time, and vacancy time of each section in the target section family. If the ship section construction cycle planning table simultaneously satisfies P w ≥0 and P u If the value is ≥0, then it is marked as a feasible planning table; S602. Reduce the construction cycle R by one basic time unit, and then correspondingly create a ship section construction cycle planning table. If the ship section construction cycle planning table simultaneously satisfies P... w ≥0 and P u If the value is ≥0, then it is marked as a feasible planning table; S603. Repeat step S602 until the construction cycle R is reduced to one basic time unit, and finally one or more feasible plans are formed. Then select the feasible plan with the smallest construction cycle R as the final ship section construction cycle plan.

9. The ship block construction cycle planning method according to claim 8, characterized in that, The basic unit of time is the day.

10. The ship block construction cycle planning method according to claim 1, characterized in that, In the process of planning the construction cycle of a ship section, several constraints are also considered, including the number of personnel, the number of cranes, the amount of materials, the number of tools and fixtures, and the continuity of the work process. Each constraint corresponds to a preset threshold, and in the final ship section construction cycle plan, each constraint does not exceed its respective preset threshold.

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