JP2001159907A - Production planning system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To create a production plan suitable for a production line consisting of forming processes and working processes by considering not only the production adjustment of the forming processes but also the production adjustment of the working processes. SOLUTION: The production planning system is provided with a production process allocation part for allocating parts and products to multiple forming processes and working processes on the basis of the number of products required to be replenished as stocks, a load judgmnet part 1c to be a load adjusting means for executing the load adjustment of a forming process and a working process generating load over when the parts and the products are allocated to respective processes by the allocation part 1b, a process-to-be-processed determination part 1d, and a production amount adjustment part 1e. A production plan is created by allocating respective parts to practical forming processes on the basis of the required quantity of adjustment after adjusting the loads of respective processes by the load adjusting means.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is applied to a production line having a plurality of molding steps and a processing step of assembling a product using parts molded in these molding steps. The present invention relates to a production plan creation system of an inventory replenishment method for creating a production plan by using a stock replenishment method.

[0002]

2. Description of the Related Art As an example of a conventional production plan creation system, there is a production plan fine-tuning system disclosed in Japanese Patent Publication No. 7-43746.

This production plan fine-tuning system determines the load of each production process of parts based on the product production plan during a predetermined planning period created by the production planning system, and calculates the determined load and the planning period. By calculating the difference between the production capacity of each production process and the load of the production process with the largest difference to other production processes, the difference between the load and production capacity of all the production processes is calculated. The goal is to make it as small as possible.

According to this production plan fine adjustment system, it is a precondition that the created production plan can be finally executed during a predetermined planning period by performing fine adjustment. However, for example, in the case where a required number of products are shipped according to an order, the product production method predicts the amount of shipment and stores a certain number of products in a warehouse in advance. This is an inventory replenishment type in which the product remanufacturing is performed by predicting the out-of-stock date to calculate the required inventory replenishment amount. According to this method, especially when the order quantity of products fluctuates greatly,
It is not possible to create a product production plan that satisfies all inventory replenishment requirements in terms of the production capacity of the parts production process. Therefore, even if the production plan is fine-tuned using the above-described production plan fine-tuning system, there is a problem that the load of all the production processes cannot be reduced during the planning period.

Therefore, the present applicant has proposed a production planning system described in Japanese Patent Application No. 10-138728 as one means for solving such a problem. This production planning system adjusts the production amount before assigning it to the production process.When calculating the stock replenishment request amount, the system calculates the product out-of-stock date and calculates the product out-of-stock date. Then, the production plan is created after the load is cut for the urgent part (the part corresponding to the product with the latest out-of-stock forecast date) so that the load does not exceed all the processes. .

[0006]

However, the actual production process is not limited to the molding process, but includes a molding process and a processing (assembly) process. In other words, a manual assembly process is required after the molding process. In some cases, there is a possibility that a situation may occur in which even if molding can be performed, assembly processing cannot be performed due to lack of manpower.

In this case, the production planning system described above does not consider the load adjustment in the machining process, and therefore is not sufficient for the production planning of a production line including such a molding process and a machining (assembly) process. The problem that it was not able to cope with was left.

The present invention has been made in order to solve such a problem. The purpose of the present invention is to consider not only the production adjustment in the molding process but also the production adjustment in the machining process. And a processing (assembly) process.

By the way, in the forming step, it is necessary to calculate the load for each part, but in the processing step, it is necessary to calculate the load for each product. Although the forming step is a mechanical step, the processing step is a manual operation, and the load-based man-hours can be adjusted. Furthermore, when actually piled up, in the molding process,
The operation rate does not become 100% due to the setup change time of the molding machine, temporary stoppage of the factory line due to noise, etc., so accurate load adjustment cannot be performed unless load adjustment considering the operation rate is performed. .

The present invention takes into consideration the conditions specific to a production line including such a molding step and a processing step.

[0011]

In order to solve the above-mentioned problems, a production planning system according to the present invention has a plurality of molding steps and a processing step of assembling a product using parts molded in these molding steps. An inventory replenishment type production plan creation system that is applied to a production line and creates a production plan based on a product inventory replenishment request amount, wherein the plurality of molding processes and the processing steps are performed based on a product inventory replenishment request amount. Means for allocating parts and products to
As a result of allocating parts and products to each process by the process allocating means, a load adjusting means for performing a load adjustment of the molding step and a load adjustment of the processing step is provided for a molding step and a processing step in which an overload occurs. Each part is assigned to an actual process and a production plan is created based on the required adjustment amount after the load of each process is adjusted by the load adjusting means.

According to the present invention having the above features,
Since the load adjustment of the molding process and the load adjustment of the processing process are performed by the load adjustment means, if there is a manual assembly process after the molding process, the situation that the assembly process cannot be performed due to shortage of labor even if the molding can be performed does not occur. .

Further, the production plan creation system of the present invention comprises:
In the above configuration, the load adjusting means deletes the production plan of the product with the latest out-of-stock predicted date among the products assigned to the process for the machining process in which the load is over, thereby performing the machining in the process. Adjust the load so that it is within the capacity, and for the molding process where overload occurs, delete the production plan of the part related to the product with the latest out-of-stock forecast date among the parts assigned to that process. ,
It is characterized in that the load is adjusted so as to be within the molding ability in the process.

According to the present invention having such features,
By separately managing the load adjustment in the molding step and the load adjustment in the processing step, a more realistic load adjustment can be realized.

Further, the production planning system of the present invention
In each of the above configurations, when the load adjustment of the product is performed in the processing step, the load adjustment unit also performs the load adjustment of the part in the molding step to which a part corresponding to the load adjustment is allocated, and performs the component adjustment in the molding step. When the load adjustment is performed, the load adjustment of the product related to the component subjected to the load adjustment is also performed in the machining process.

According to the present invention having such features,
By managing the load adjustment in the molding step and the load adjustment in the processing step in association with each other, a production plan for the molding step and the processing step as a whole can be created in a more realistic manner.

Further, the production plan creation system of the present invention
In each of the above configurations, the load adjusting means sets a molding ability and a machining ability as a criterion for determining an overload in each step using the molding load and the machining load as parameters. Also, the production plan creation system of the present invention
The above configuration is characterized in that in the molding step, the operating rate is used as a parameter, and the operating rate is multiplied by the molding capacity. In the processing step, the number of processing personnel is used as a parameter, and the number of processing personnel is multiplied by the processing capacity.

According to the present invention having such features,
In the molding process, a pile of parts is piled up, and a parameter called an operation rate is multiplied by the molding capacity, so that a more realistic overload judgment criterion can be set. In the machining process, piles are created in product units, and the conditions for adjusting the load are as follows: a parameter called the number of machining personnel is set, and the machining capacity is multiplied by a parameter called the number of machining personnel. Criterion can be set.

Further, the production planning system of the present invention
The above configuration is characterized in that the operation rate and the number of processing personnel, which are parameters, are changed in accordance with changes in the past required stock replenishment and the required adjustment. That is,
The operating rate and the number of machining personnel, which are the two criteria for eliminating overload, are automatically adjusted according to the fluctuation trend of the required inventory replenishment and the required adjustment (the required quantity after adjusting the production volume) on a fixed basis. By changing, the optimal load adjustment can be performed. Here, the "requested replenishment amount" refers to the replenishment amount of the stock in the conventionally known inventory replenishment method, and is a required production amount corresponding to the set inventory amount. The “requested adjustment amount” is the amount of the replenishment request amount that can be actually allocated to the process plan in consideration of the production capacity of the process.

That is, the total weight of the replenishment request amount and the total weight of the adjustment request amount for each planning are stored.
The criterion of load over (load adjustment criterion) is varied according to both tendencies. In other words, the change in the replenishment request amount will take into account the change in the order amount, and the change in the adjustment request amount will be
Since the degree of follow-up of the molding amount with respect to the fluctuation of the order quantity is shown, it is possible to judge whether or not the current production plan is appropriate by looking at these behaviors. Then, an optimum production plan can be created by changing the determination standard for overload from the result to an optimal state. In addition, when adjusting the process load, a manual processing step can be dealt with by increasing or decreasing the number of personnel, but it is not always possible to increase or decrease the number of molding machines in the molding step. However, in the actual molding process, since a margin such as a temporary stop of a factory line or a changeover time due to noise or the like is provided, the molding load factor in a normal operation is, for example, a load factor of about 70 to 80%. Let me. For this reason, this load factor (operating rate) can be increased by increasing the number of setup change personnel or shortening the setting of the recovery time when the factory line is temporarily stopped due to noise or the like. Therefore, it is possible to change the load factor (operating rate) also in the molding process.

[0021]

Embodiments of the present invention will be described below with reference to the drawings.

The production plan creation system of the present invention is applied to a production line having a plurality of molding steps and a processing step of assembling a product using parts molded in these molding steps. That is, this production plan creation system is a system that creates a product production plan for a predetermined planning period in accordance with inventory replenishment request data of a product composed of at least one part, and according to the product production plan. In the case of producing a part (in the present embodiment, molding by a molding machine), if there is a molding process in which the molding of the part cannot be completed within the planning period and an overload occurs, the product is not manufactured during the planning period. The load of the molding process is adjusted by canceling the molding of a predetermined part or reducing the molding amount of the part as long as the part does not run out.

FIG. 1 is a block diagram of a production plan creation system according to this embodiment.

This production plan creation system is a system for creating a production plan of a product during a predetermined planning period in accordance with a stock replenishment request amount of a product composed of at least one part, and totally controls the entire system. Main control unit (hereinafter referred to as “CPU”)
1) and a storage device 2 connected to the CPU 1
An input / output control unit 3 interconnected with the CPU 1;
An input device 4 composed of a pointing device such as a keyboard and a mouse, a display device 5 used for monitoring input data and output data, and an output for outputting calculation results and the like, connected to the CPU 1 via the input / output control unit 3. And an apparatus 6.

The CPU 1 executes an OS (Operating)
system, etc., a program that defines processing procedures to be performed using the system, and an internal memory for storing required data.
a, a production process allocating unit 1b, a load determining unit 1c, a processing target production process determining unit 1d, a production amount adjusting unit 1e, and an operation control unit 1f.

The part developing section 1a is a means for calculating the planned production quantity of the product in accordance with the requested stock replenishment of the product, and developing the planned production quantity into the molding quantity of the part in a state associated with the product.

The production process allocating unit 1b sequentially allocates the molding of each component to a plurality of molding processes in a piled manner according to the molding amount of the component developed by the component developing unit 1a. This is a means for sequentially allocating products related to (1) in a pile in the processing process. Here, “sequentially laying out in piles” means the following way of allocating. In other words, in the case of the molding process, it means that among the products related to the developed parts, the parts related to the product with the earliest out-of-stock forecast date described later are allocated in order from the part related to the developed part. This means that among the products related to the parts allocated to the molding process, the products with the predicted out-of-stock date described later are allocated in order from the earliest product. In other words, the components and products that are assigned to the last are less likely to be out of stock immediately.

As a result of allocating the molding of each component to each molding process by the production process allocating unit 1b, the load determining unit 1c determines whether or not there is a production process in which the production of the component cannot be completed within the planning period and an overload occurs. Judge. Further, as a result of allocating the processing of the product to the processing process by the production process allocating unit 1b, it is a means for determining whether or not the production of the product cannot be completed within the planning period and an overload occurs.

When the load determining unit 1c determines that there is one molding process in which the load is over, the production process determining unit 1d determines the molding process in which the load is over by the production process. When the load determining unit 1c determines that there are a plurality of molding processes in which the load is over, the molding process having the highest load among the plurality of molding processes in which the load is over is processed. Determined as a process. When the load determining unit 1c determines that the processing step is overloaded, the processing unit determines the processing step as a target production step.

According to the decision made by the process-to-be-processed determining step 1d, the production amount adjusting unit 1e determines, for the machining process in which the overload occurs, the product with the latest out-of-stock predicted date among the products assigned to the machining process. By deleting the production plan, the load is adjusted to be within the processing capacity in the process. In addition, in accordance with the determination by the process-to-be-processed determining unit 1d, for a molding process in which an overload occurs, a production plan for a component related to a product having the latest predicted out-of-stock date among components assigned to the molding process is determined. This is a means for adjusting the load by removing it so that it is within the molding capability in that step. In this case, when the load of the product is adjusted in the processing process, the load of the component is also adjusted in the molding process to which the component related to the load adjustment is allocated, and the load of the component is adjusted in the molding process. In such a case, the load adjustment of the product related to the component subjected to the load adjustment is also performed in the processing step. In addition, the production amount adjustment unit 1e can set the molding ability and the machining ability as a criterion of overload in each process using the molding load and the machining load as parameters. Specifically, in the molding process, the operating rate is used as a parameter, and this operating rate is multiplied by the molding capacity to determine the overload. In the processing step, the number of processing personnel is used as a parameter to multiply the processing capacity by the processing capacity. It is also used as a criterion of overload. Further, the operation rate and the number of processing personnel, which are parameters, can be changed in accordance with changes in the past stock replenishment request amount and adjustment request amount.

The operation control section 1f causes the load judging section 1c to overload when the molding of the component is allocated to each molding step and when the processing of the product related to the allocated component is allocated to the processing step. Until it is determined that there is no molding step and processing step, the processing operations in the part expanding means 1a, the production step allocating section 1b, the load determining section 1c, the target production step determining section 1d, and the production amount adjusting section 1e are sequentially executed. Means.

The storage device 2 includes a hard disk,
It is composed of a flexible disk, an optical disk, or the like, and is composed of an inventory replenishment request amount file 2a, a parts configuration file 2b, a production plan file 2c, a production capacity file 2d, a processing target production process file 2e, and an out-of-stock prediction file 2f. And are stored.

The requested stock replenishment amount file 2a is a file in which the requested stock replenishment amount data indicating the requested stock replenishment amount is recorded in advance. FIG. 2 shows an example of the inventory replenishment request amount data. The stock replenishment request amount (hereinafter simply referred to as “request amount” in FIG. 2) of the product of product number A (hereinafter, simply referred to as “product A”) is 100 pieces, and the product of product number B (hereinafter, simply referred to as “request amount”). , Simply called “Product B”) is 1
The inventory replenishment request quantity of the product of product number C (hereinafter, simply referred to as “product C”) is 100 pieces, and the inventory replenishment request of the product of product number D (hereinafter, simply “product D”) is 50 pieces. The quantity is 100 pieces and the product of product number E (hereinafter, referred to as
The requested amount of stock replenishment for the product “product E”) is 100 pieces, and the requested quantity of stock replenishment for the product of the product number F (hereinafter, simply referred to as “product F”) is 150 pieces.

The component configuration file 2b is a file to which related information for associating a component with a product is added, and that records component configuration data indicating components constituting each product. FIG. 3 shows an example of the component configuration data. The product A includes one part having a part number V (hereinafter simply referred to as “part V”) and a part having a part number Y (hereinafter simply referred to as “part Y”).
The product B is composed of two parts. The product B has one part with the part number X (hereinafter, simply referred to as “part X”), one part V, and the part with the part number R (hereinafter, simply “part R”). That)
The product C is composed of two parts having a part number Z (hereinafter, simply referred to as “part Z”) and one part X, and the product D is composed of one part R. , A part number S (hereinafter, simply referred to as “part S”), and a product E is composed of two parts R and a part Z1.
The product F is composed of one part S1.

The production plan file 2c is stored in the parts development section 1a.
This is a file for recording the production plan data obtained by the development processing by and the production plan data obtained by the load adjustment processing by the production amount adjustment unit 1e. This production plan file 2c is shown in FIG. 8, and will be described in detail in a procedure for creating a production plan later.

The production capacity file 2d is a file for recording production capacity data (molding capacity data and processing capacity data) indicating the production capacity of each production step (molding step and processing step). This production capacity data is data serving as a criterion for determining an overload. Here, in the molding process,
By multiplying the molding capacity by a parameter called the operating rate, a more realistic overload judgment criterion can be set. Also, in the machining process, a parameter called the number of machining personnel is set, and the parameter of the number of machining personnel is multiplied by the machining capacity so that a more realistic load over judgment criterion can be set.

That is, in the molding process, the value calculated by the following equation (1), planning period (days) × 24 (hours) × operating rate (%) (1) In the machining process, the value calculated by the following equation (2), planning period (days) × 7.5 (hours / person) × number of machining personnel (2) is used as a criterion for determining the overload.

That is, in the description here, the criterion is time. For example, the planning period is 7 days,
Assuming that the operation rate is 80%, the criterion of the molding process is 7 × 24 × 0.8 = 13.4 (time) from the above equation (1).
Assuming that the number of machining personnel is 50, the criterion for the machining process is 7 × 7.5 × 50 = 2625 from the above equation (2).
Time.

However, in the present embodiment, it is easier to understand these times by replacing them with the number of parts or products in the following description. That is, the time calculated by the above equation (1) is
By dividing by the unit molding time of an arbitrary part, the molding capability of the molding process can be represented as the number of molded parts. Similarly, by dividing the time calculated by the above equation (2) by the unit assembly time of an arbitrary product, the processing capability of the processing step can be expressed as the number of assembled products.

FIG. 4A shows an example of a criterion (molding ability) of each molding step when the molding ability is represented by the number of molded parts, and FIG. 5 shows an example of a criterion (machining capability) of a machining process when the number of assembly is expressed by the number of pieces. In the present embodiment, it is assumed that a part is molded using three molding steps (that is, three production facilities), and the first molding step L1 is performed by converting the part R or the part X into 6 parts per day.
Zero molding can be performed, the second molding step L2 can mold 60 parts S or Y in one day, and the third molding step L3 can mold 60 parts V or Z in one day. Have the ability to be. In other words, this is a criterion for determining an overload in each molding step. In the processing step, each of the products A to F has an ability to assemble 90 pieces in one day. In other words, this is a criterion for determining the load over in the machining process. However, here, for simplicity of description, both the molding step and the processing step are standardized to one criterion (60 in the molding step and 90 in the processing step). However, in actuality, it is natural that the molding ability may be different depending on the part to be molded, and it is natural that the processing ability may be different depending on the product to be assembled. In the above description, the molding process is performed in the first to third steps.
Are described as three molding steps, but the classification of the molding steps is as follows: S class (350
Tons), F class (550 tons or less, M class (8
50 tons or less) and L class (more than 850 tons). Each class has S15, S17, S2
2, S35, F45, F55, F55A, M85, L1
There are molding processes (molding machines) such as 05 and L180, but here, the above three molding processes will be described.

The processing target production process file 2e is a file for recording processing target production process data obtained by the processing by the processing target production process determining unit 1d. For example, it is composed of data indicating a production process selected as a production process to be processed, data indicating a part produced in the production process, and data indicating a product related to the part. The processing target production process file 2e will be described in detail in a procedure for creating a production plan later.

The out-of-stock predicted file 2f is a file in which out-of-stock predicted data indicating a predicted out-of-stock date of a product is recorded in advance. FIG. 5 shows an example of the out-of-stock prediction data.
The out-of-stock prediction data is created based on data indicating the stock amount and the average shipment amount of each product as shown in FIG. 6, for example. According to FIG. 6, the stock quantity of the product A is 100 pieces, the average shipment quantity is 10 pieces per day,
Has an inventory of 150 units and an average shipment of 1 per day
0 pieces, the stock quantity of the product C is 70 pieces, the average shipment quantity is 10 pieces per day, the stock quantity of the product D is 50 pieces, the average shipment quantity is 10 pieces per day, E
Has an inventory of 20 units and an average shipment of 10 units per day.
And the stock quantity of the product F is 70 pieces, and the average shipment quantity is 10 pieces per day. Thus, as shown in FIG. 5, product A is out of stock after 10 days, product B is out of stock after 15 days, product C is out of stock after 7 days, product D is out of stock after 5 days, and product E is out of stock 2 days. It can be predicted that the product F will be out of stock later and the product F will be out of stock after 7 days.

Next, a processing procedure for performing load adjustment (adjustment of production amount) of parts and products using the production plan creation system shown in FIG. 1 will be described with reference to a flowchart shown in FIG.

First, the parts development unit 1a creates a production plan by obtaining the production plan quantity of the product in accordance with the required inventory replenishment data recorded in the required inventory replenishment file 2a, and creates the production plan as production plan data. File 2
c, and according to the component configuration data recorded in advance in the component configuration file 2b, the production plan quantity is developed into the component production quantity (molding quantity) in a state of being associated with the product (step S1). FIG. 8A shows an example of the production plan data created in step S1. Since the product production plan is created according to the required inventory replenishment, the production planned quantity of each product is equal to the respective required inventory replenishment (see FIG. 2). That is, the production planned quantity of the product A is 100 pieces, the production planned quantity of the product B is 150 pieces, the production planned quantity of the product C is 100 pieces, the production planned quantity of the product D is 100 pieces, The production planned quantity of the product E is 100 pieces, and the production planned quantity of the product F is 150 pieces. Also,
In this step S1, 100 products A are 100
Parts V and 200 parts Y, 150 products B are 150 parts X, 150 parts V and 150 parts
100 parts C are developed into 200 parts Z and 100 parts X, 100 products D are developed into 100 parts R and 100 parts S,
100 products E are developed into 200 parts R and 100 parts Z, and 150 products F are developed into 150 parts S.

Next, the production process allocating unit 1b sequentially allocates the molding of each component to a plurality of molding processes according to the production amount of the component developed by the component developing unit 1a, and allocates the molding to the plurality of molding processes. Products related to the attached parts are sequentially allocated in a piled-up manner in the processing process (step S2). In other words, in the molding process, among the products related to the developed parts, the parts related to the product with the earliest out-of-stock predicted date recorded in the out-of-stock prediction file 2f are sequentially allocated, and in the processing step, the molding is performed. Among the products related to the parts allocated to the process, the products are allocated in order from the product with the earliest out-of-stock predicted date recorded in the out-of-stock predicted file 2f. In other words, in this case, first, the product E whose out-of-stock predicted date is two days later and the components R and Z related to this product E are allocated to the respective processes, and then the product D whose out-of-stock predicted date is 5 days later is assigned to each process. Parts R and S related to this product D are allocated to respective processes, and then products C or F whose out-of-stock predicted date is 7 days later.
And a part Z, X or part S related to the product C or F is allocated to each process, and then a product A whose predicted out-of-stock date is 10 days later and a part V related to the product A,
Y is assigned to each process, and finally, a product B with a predicted out-of-stock date of 15 days later and components X, V, and R related to the product B are assigned to each process.

FIG. 9 (a) shows the result of allocating parts and products to each molding step and processing step in this way. In the expression a (b) = c in FIG. 9, a represents the part number of the part to be produced, b represents the product number of the product related to the part a, and c represents the number of parts molded.

As shown in FIG. 9A, the first molding step L
1 includes 200 parts R related to the product E and 1 part R related to the product D in order from the earliest out-of-stock prediction date.
00 parts, 100 parts X related to the product C, 150 parts X related to the product B, and 150 parts R related to the product B are arranged in a pile. Also,
In the second molding process L2, 100 parts S related to the product D, 150 parts S related to the product F, and 20 parts Y related to the product A
0 pieces are allocated in piles. In the third molding step L3, 100 parts Z related to the product E, 200 parts Z related to the product C, and 15 parts V related to the product B are arranged in the order from the earliest out-of-stock prediction date.
0 parts and 100 parts V related to the product A are allocated in piles. In the processing step, 100 products E and D
, 100 products C, 150 products B, 100 products A, and 100 piles.

Next, based on the result of allocating the molding of each part and the processing of each product to each molding step and processing step in this manner, the load determining unit 1c firstly performs the processing step within the planning period within the planning period. It is determined whether the assembly of the product cannot be completed and an overload occurs (step S3). In the present embodiment, the planning period is set to 7 days, and according to the processing capacity of the processing step shown in FIG. 4B, 90 products can be assembled per day. Individual products can be assembled. That is, the overload determination criteria are 630. On the other hand, as shown in FIG. 9A, since 700 products are allocated to the processing step, an overload occurs in the processing step, and the determination result in step S3 is Yes. Therefore, the processing target production process determination unit 1d determines this processing step as a processing target production process, and records it as the processing target production process data in the processing target production process file 2e (step S4). on the other hand,
If the result of the determination in step S3 is No, the operation proceeds to step S7 in order to determine whether or not an overload has occurred in the molding process.

Next, in the production amount adjusting section 1e, step S
For the machining process determined as the production process to be processed in 4, the products that are overloaded (exceeding the judgment criterion) in order from the product with the latest out-of-stock predicted date among the products assigned to the machining process. The production plan of (product) is deleted (step S5). In this case, the product A (= 1
8), the production plan quantity of the product A in the production plan data recorded in the production plan file 2c is changed to 0, as shown in FIG. 8B. Further, with the deletion of the product A in the processing step, the production plan of the part related thereto is deleted from each molding step to adjust the production amount (step S6). That is, the parts related to the product A are the parts V and Y from the part configuration file 2b, and the molding steps for molding these parts are L2 and L3.
Therefore, the parts V and Y are obtained from the molding steps L2 and L3.
Delete a production plan.

FIG. 9 (b) shows the result of the allocation of each molding step and processing step after the production plan of the product A and the parts V and Y related thereto is deleted. As is clear from the comparison between the allocation result shown in FIG. 9A and the allocation result shown in FIG. 9B, the production of the product A has been deleted from the processing step, and the production of the part Y has been omitted from the second molding step. The production of the part V has been deleted from the third molding step L3. As a result, production of 600 products will be allocated to the processing process,
Overload has been resolved. Meanwhile, at this stage, the first
In the molding step L1 and the third molding step L3, overload still occurs.

Next, in each molding step, the load determining unit 1c determines whether or not the molding of the component cannot be completed within the planning period and an overload occurs (step S7). In the present embodiment, the planning period is set to 7 days, and according to the molding capability of each molding process shown in FIG. 4A, each molding process can mold 60 parts each day, 420 in each molding process within the planning period
Individual parts can each be molded. That is, there are 420 overload determination criteria. And
At this time (when the overload of the machining process is eliminated)
Thus, the production of a total of 700 parts is allocated to the first molding step L1, and the total of 250 parts is allocated to the second molding step L2.
The production of individual parts is allocated, and the third molding process L3
Has a total production of 650 parts.
That is, the load is excessive in the first molding process L1 and the third molding process L3, and the determination result in step S7 is Yes. When the result of the determination in step S7 is No, the load over has been resolved in all the molding steps, and the load adjustment processing ends.

When the result of the determination in step S7 is Yes, the target production process determining unit 1d determines a molding process to be processed (step S8). Here, the first molding process L1 with the highest load is to be processed.

For this reason, in the production quantity adjusting unit 1e, among the parts assigned to the first production process L1, the parts (for which the out-of-stock predicted date is related to the product with the latest out-of-stock date) are overloaded in order. In addition to deleting the production plan of the part exceeding the determination standard), the product related to this part and other parts related to this product are deleted from the production plan of each process (step S9). In this case, since parts are piled up in the molding process, as a deletion procedure, first, a product related to this part is searched from the component configuration file 2b, and the production plan of this product is deleted from the machining process. Then, the production plan of the part related to the product is deleted from the assigned molding process. That is, in this case, the parts overloaded are X and R, and the product related to this part is the product B from the component configuration file 2b. Therefore, the production plan of this product B is deleted from the machining process. Then, the production plan of the parts X and R related to the product B is deleted from the first molding step L1, and the production plan of the part V related to the product B is deleted from the third molding step L3. Further, since the product B has been deleted from the molding step and the processing step, the production plan of the product B is deleted from the production plan data of the production plan file 2c shown in FIG. 8B, and as shown in FIG. The production plan quantity of the product B is changed to 0 pieces.

FIG. 9C shows the allocation result of each molding step and processing step after deleting the plan of the product B and the parts X, R, and V related thereto. As is clear from the comparison between the allocation result shown in FIG. 9B and the allocation result shown in FIG. 9C, the production plan of the product B has been deleted from the machining process, and the production plans of the parts X and R have been deleted. It has been deleted from the first molding step L1, and the production plan of the part V has been deleted from the third molding step L3. As a result, the production of 400 parts is allocated to the first molding step L1, and the production of 300 parts is allocated to the third molding step L3, and the overload is eliminated in all the molding steps. ing. In other words, when the process returns from step S9 to step S7, in this case, the determination result in step S7 is No. Therefore, the production plan shown in FIG. 8C is changed to the final production plan (adjusted production request amount). As
The process ends. In addition, even if the processing of step S9 is performed, if the overload still occurs in any molding process, the processing of steps S7 to S9 is repeated until the overload is eliminated in all the molding processes. .

As described above, in the present embodiment, not only the load adjustment in the molding step but also the subsequent processing step (assembly step)
By performing the load adjustment at the same time, if there is a manual assembly process after the molding process, the situation that the assembly process cannot be performed due to shortage of labor even if the molding can be done will not occur, and the molding process and the processing process will be It is possible to adjust the load according to the production line.

In this case, in the above-described embodiment, as the criterion for each molding step and the criterion for the processing step, the values calculated by the above equations (1) and (2) are used. If the criterion is changed in some cases, the load can be adjusted more realistically.

That is, the total weight of the replenishment request amount and the total weight of the adjustment request amount for each time of planning are stored in an area (not shown) of the storage device 2, and the criterion of the overload is changed according to the tendency of both. What should be done is. In other words, the change in the replenishment request amount will take into account the change in the order amount, and the change in the adjustment request amount indicates the degree of follow-up of the molding amount with respect to the change in the order amount. It can be determined whether the current production plan is appropriate. Then, an optimum production plan can be created by changing the determination standard for overload from the result to an optimal state.

More specifically, as described above, the criterion of the molding process is [planning period (days) × 24 (hours) × operating rate (%)].
[Planning period (days) x 7.5 (hours / person) x number of processing personnel]. Here, assuming that the operation rate, which is a parameter, is fixed to 80%, which is an empirical numerical value, and the number of machining personnel is fixed to, for example, 50 by limiting the number of field workers (in the case of the above embodiment). No matter how large a replenishment request amount comes, there may be inflexible load adjustment such that the adjustment request amount for process allocation hardly changes. That is, FIGS. 9 (a) to 9 (c)
As shown in (2), since a part is deleted in relation to a product, a considerable amount is deleted, resulting in an excessively deleted state.

Therefore, in the present embodiment, the total amount (unit is weight) of the replenishment request amount and the total amount (unit is weight) of the adjustment request amount in the past three times of planning are stored in the storage device 2. In advance, linear approximation is performed according to each transition situation. FIG. 10 shows the relationship of the approximate straight line between the replenishment request amount and the adjustment request amount at this time in the form of a correspondence table. The meaning of each area in this table is as described below.

In the case where both the replenishment request amount and the adjustment request amount are increasing. In this case, since the order amount increases and the process allocation amount (number) also increases accordingly, it is necessary to operate the parameters. Without the status quo.

In the case of (a), although the requested replenishment amount is increasing, the adjustment request amount is flat. In this case, the process allocation amount (number) is flat even though the order receiving amount is increased. Therefore, the parameter operation is performed in a direction in which the process allocation amount (number) increases.

The case in which the adjustment request amount is decreasing although the replenishment request amount is increasing. In this case, the process allocation amount (number) is increased even though the order amount is increasing.
Is decreased, the parameter operation is performed in a direction to increase the process allocation amount (number).

Although the replenishment request amount is flat,
In this case, the adjustment request amount is increasing. In this case, although the order allocation amount has not increased, the process allocation amount (number) has increased, so the parameter operation has to be performed in the direction in which the process allocation amount (number) decreases. Do.

Is the case where both the replenishment request amount and the adjustment request amount are flat. In this case, since both the order reception amount and the process allocation amount (number) are stable, the current state is maintained without operating the parameters.

Although the replenishment request amount is flat,
In this case, the adjustment request amount is falling. The order amount is stable, but the process allocation amount (number) is decreasing. Therefore, the parameter operation is performed in the direction in which the process allocation amount (number) increases.

In the case of (a), although the replenishment request amount is falling, the adjustment request amount is rising. In this case, the parameter operation is performed in a direction in which the process allocation amount (number) decreases.

In the case where the adjustment request amount is stable despite the decrease in the replenishment request amount, in this case, the process allocation amount (number) is reduced even though the order amount is decreasing.
Is flat, the parameter operation is performed in the direction in which the process allocation amount (number) decreases.

In the case where both the replenishment request amount and the adjustment request amount are falling, in this case, the order receiving amount has decreased and the process allocation amount (number) has also decreased. Maintain the status quo.

By automatically adjusting the production amount according to the demand by such parameter operation, a more optimal production plan can be created in accordance with the demand fluctuation.

[0070]

According to the production planning system of the present invention, the load adjustment means performs the load adjustment in the molding process and the load adjustment in the machining process. Even if it is possible, the situation that assembly processing cannot be performed due to lack of labor does not occur. That is, the load can be adjusted more realistically, so that a more appropriate production plan can be created.

Further, according to the production planning system of the present invention, in the molding process, piles are made in units of parts, and by multiplying the molding capacity by a parameter called the operating rate, a more realistic load over judgment criterion can be obtained. Can be set,
In addition, in the machining process, a pile of individual products is piled up, and by multiplying the machining capacity by the parameter of the number of machining personnel, it is possible to set a more realistic overload judgment criterion, so that the load adjustment is in line with reality. As a result, a more appropriate production plan can be created.

Further, according to the production plan creation system of the present invention, the operating rate and the number of machining personnel, which are the two criteria for eliminating the overload, are set on a constant basis in accordance with the fluctuation tendency of the required inventory replenishment and the required adjustment. Since it is configured to change automatically, the adjustment of the production amount can be automatically adjusted according to the demand, so that a more optimal production plan can be created according to the fluctuation of demand.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating an embodiment of a production plan creation system according to the present invention.

FIG. 2 is an explanatory diagram showing an example of required inventory replenishment amount data recorded in a required inventory replenishment amount file constituting the production plan creating system shown in FIG. 1;

FIG. 3 is an explanatory diagram showing an example of component configuration data recorded in a component configuration file constituting the production plan creation system shown in FIG. 1;

FIG. 4 is an explanatory diagram showing an example of production capacity data recorded in a production capacity file constituting the production plan creation system shown in FIG. 1;

FIG. 5 is an explanatory diagram showing an example of out-of-stock prediction data recorded in an out-of-stock prediction file included in the production plan creation system shown in FIG. 1;

FIG. 6 is an explanatory diagram showing an example of data indicating a stock amount and an average shipment amount of each product used when creating the out-of-stock prediction data shown in FIG. 5;

FIG. 7 is a flowchart illustrating a procedure for creating a product production plan using the production plan creation system shown in FIG. 1;

FIG. 8 is an explanatory diagram showing an example of production plan data created by using the production plan creation system shown in FIG. 1;

FIG. 9 is an explanatory diagram showing an example of a result of allocating parts to a plurality of production processes according to a production plan created by using the production plan creation system shown in FIG. 1;

FIG. 10 is an explanatory diagram showing a relationship between an approximate straight line between a replenishment request amount and an adjustment request amount.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 CPU 1a Parts development part 1b Production process allocation part 1c Load judgment part 1d Processing target production process determination part 1e Production amount adjustment part 1f Operation control part 2 Storage device 2a Inventory replenishment request amount file 2b Parts configuration file 2c Production plan file 2d Production Performance file 2e Production process file to be processed 2f Out-of-stock forecast file 3 Input / output control unit 4 Input device 5 Display device 6 Output device

Claims (6)

[Claims] The present invention is applied to a production line having a plurality of molding steps and a processing step of assembling a product using parts molded in these molding steps, and creates a production plan based on a required stock replenishment amount of the product. An inventory replenishment type production plan creation system, comprising: a process allocating means for allocating parts and products to the plurality of molding processes and the machining processes based on a product replenishment request amount; For a molding process and a machining process in which an overload occurs as a result of being assigned to each process, a load adjusting means for performing a load adjustment in the molding process and a load adjustment in the machining process is provided. A production plan creation system characterized by allocating each part to an actual molding process and creating a production plan based on the adjusted required amount after adjustment. Stem. 2. The method according to claim 1, wherein the load adjustment unit deletes a production plan of a product having a latest out-of-stock predicted date among the products assigned to the process in the process in which the load is over. Adjust the load so that it is within the processing capacity of the part, and for the molding process where the load is over, delete the production plan of the part related to the product with the latest out-of-stock forecast date among the parts allocated to that process By that
2. The production plan creation system according to claim 1, wherein the load is adjusted so as to be within the molding capacity in the process. 3. When the load adjustment of the product is performed in the processing step, the load adjustment means also adjusts the load of the part in the molding step to which a part related to the load adjustment is allocated. 3. The production plan creation system according to claim 2, wherein when the load adjustment of the component is performed, the load adjustment of the product related to the component subjected to the load adjustment is also performed in the processing step. 4. The method according to claim 1, wherein said load adjusting means sets a molding ability and a machining ability as a criterion for determining an overload in each step by using the molding load and the machining load as parameters. Production planning system described in 1. 5. The method according to claim 1, wherein the operating ratio is multiplied by the molding capacity in the molding step, and the operating capacity is multiplied by the machining capacity in the processing step. The production plan creation system according to claim 4, wherein 6. The production plan creating system according to claim 5, wherein the operating rate and the number of processing personnel, which are the parameters, are changed in accordance with a change in a past stock replenishment request amount and an adjustment request amount. .