JP2009075631A - Production schedule preparation method and system therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prepare a high-quality schedule for a production line including a process for lot sizing by preparing a schedule for respective processes and an overall schedule. <P>SOLUTION: This production schedule preparation method has: process schedulers 11-14 each preparing a process schedule of its own process; and an overall scheduler 20 preparing an overall schedule from the respective schedules. The process scheduler has: a process schedule preparation part 112 preparing the schedule of the own process from a restriction condition; and a process cost simulation part 114 calculating cost information of the prepared process schedule. The overall scheduler has: an overall schedule preparation part 201 preparing the overall schedule from the respective process schedules; an overall cost simulation part 202 calculating cost information related to work procedure efficiency of the prepared overall schedule; and a correction processing part (207, 111) creating a new restriction condition for correcting the respective process schedules from the cost information. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to schedule management when a plurality of types of products are produced on a production line composed of a plurality of processes, and more particularly to a production schedule creation method and a system thereof when lots need to be collected in a certain process.

  2. Description of the Related Art Conventionally, there is known a production line that is a multi-process production line that enables lots to be collected in a certain process when a plurality of types of products are produced. For example, there is a production line for a material-based industry in which an ingot forming process for creating a plurality of slabs in a melting furnace and a batch annealing process for annealing a plurality of coils at a time exist.

  In a production line that handles multiple processes, the operation conditions and capacities unique to each process are different, so that the desired production schedule differs for each process. In addition, when there is a process to perform lot collection (for example, batch annealing process that can process multiple jobs at once) on the production line, all the jobs included in the lot scheduled to be processed in its own process are processed in the previous process. If it is not completed, the process in its own process cannot be started. Therefore, if the work of the target job in the previous process is unevenly distributed in the plan period due to the result of the lot summarization, the process start in the own process is delayed, and there is a possibility that the mechanism is increased and the delivery date is delayed. As described above, the desired schedule is different for each process, and simply combining schedules that consider only the convenience of each process independently does not result in a good quality schedule as a whole. Therefore, the production schedule for each process needs to be created in consideration of the convenience of the process and the efficiency of the entire line. In general, the schedule creation considering the efficiency of the entire line has problems such as creating a high-quality plan as a whole in the shortest possible time and flexibly responding to disturbances (equipment troubles).

  In addition, in order to reduce the calculation time in consideration of lot sizing and create a high-quality schedule, a production schedule is created by backward scheduling based on the delivery date, and lot sizing is performed according to the order. This is proposed in Patent Document 1.

  The method disclosed in Patent Document 1 has the following features. 1) The production line has a step requiring lot summarization in the first step. 2) A process start time and a process end time are determined in such a manner that the process in the final process of each product is matched with the delivery date. 3) The process start time and process end time determined in 2) are determined by backward scheduling. In other words, since the job passing process, delivery time, and processing time in each process (the time to occupy the machine to perform processing) are known in advance, processing starts with the processing completion time in the final process as the delivery date Determine the time. Then, the processing start time—the lead time between processes is defined as the process end time of the previous process. By going back to the first step, a schedule is drawn up. 4) After scheduling that does not consider lot sizing is determined, lot sizing is performed according to the original processing order in a process that requires lot sizing. At this time, the contradiction of the lower process caused by collecting lots is eliminated by shifting the processing time zone in the lower process. 5) In addition, the plan will be executed by combining the rough production plan in the long-term span with the refined production plan with the plan period limited to the latest.

In other words, according to such a method, it is possible to create a production line schedule having a lot summary by complying with the delivery date by the backward scheduling method based on the delivery date. In addition, by combining the two types of production plans, the rough plan and the fine plan, the time required for the planning can be shortened. If a disturbance occurs, it is only necessary to review the coarse plan and the latest fine plan. Therefore, it can respond flexibly to disturbances.
JP2003-256020A

  However, the method of Patent Document 1 has the following problems. That is, 1) Since lots are grouped based on a schedule created based on the delivery date, it is difficult to collect lots of jobs for jobs whose delivery dates are longer than a certain period. 2) Since the processing order is determined based on the delivery date, the processing order becomes the same in a plurality of steps. Therefore, it is difficult to cope with a production line in which lots are collected using different information in a plurality of processes. 3) Since the schedule is drawn up based on the delivery date, there may be a case where productivity is remarkably lowered in a certain process, such as frequent setup.

  The present invention is for solving the above-mentioned problems, and by executing scheduling on each process side and the whole, a better quality schedule as a whole is produced for a production line including a process for batch lotting. It is an object of the present invention to provide a distributed production schedule creation method and system that can be created in a short time.

  The invention according to claim 1 is a production schedule creation system for creating a production schedule for producing a plurality of types of products by performing lot summarization in any one of a plurality of steps, Correspondingly provided, a process scheduler that creates a process schedule for its own process, and an overall scheduler that is communicably connected to each process scheduler and creates an overall schedule based on the process schedule created by each process scheduler Each of the process schedulers, a process schedule creating means for creating a process schedule of the own process based on a processing order for each product set for the own process, a combination of lots and a predetermined constraint condition; Provided in at least one of the process scheduler and the overall scheduler First evaluation information calculation means for calculating first evaluation information relating to work procedure efficiency of the created process schedule, and the overall scheduler creates an overall schedule for all processes based on each process schedule An overall schedule creating means, a second evaluation information means for calculating second evaluation information related to work procedure efficiency of the created overall schedule, and each of the process schedulers using the first and second evaluation information. Correction processing means for creating a new constraint condition for correcting the process schedule.

  The invention according to claim 11 is provided corresponding to each process, and is based on a process scheduler that creates a process schedule for its own process, and that is communicably connected to each process scheduler and created by each process scheduler. A production schedule method for producing a production schedule for producing a plurality of types of products by performing lot summarization in any one of a plurality of processes, The process schedule creating means provided in each of the process schedulers creates a process schedule for the own process based on the processing order for each product set for the own process, a combination of lots and a predetermined constraint condition, The first provided in at least one of the process scheduler and the overall scheduler The evaluation information calculation means calculates first evaluation information related to the work procedure efficiency of the created process schedule, and the overall schedule creation means provided in the overall scheduler determines the overall schedule for all processes based on each process schedule. The second evaluation information means provided in the overall scheduler calculates second evaluation information related to the work procedure efficiency of the created overall schedule, and the correction processing means provided in the overall scheduler includes: A new constraint condition for correcting each process schedule by the process scheduler is created using the first and second evaluation information.

  According to this configuration, a process schedule of its own process is created by a process scheduler provided corresponding to each process, and a process created by each process scheduler by an overall scheduler that is communicably connected to each process scheduler An overall schedule is created based on the schedule. Then, the present invention is applied to a technique for creating a production schedule for producing a plurality of types of products by collecting lots in any one of the plurality of processes. By the process schedule creation means provided in each of the process schedulers, the process schedule of the own process is created based on the processing order for each product set for the own process, a combination of lots and a predetermined constraint condition, First evaluation information relating to work procedure efficiency of the created process schedule is calculated by first evaluation information calculation means provided in at least one of the process scheduler and the overall scheduler, and the overall evaluation information is provided in the overall scheduler. An overall schedule for all processes is created based on each process schedule by the schedule creation means, and a second evaluation relating to work procedure efficiency of the created overall schedule by the second evaluation information means provided in the overall scheduler. Information is calculated. Next, a new restriction condition for correcting each process schedule by the process scheduler is created by the correction processing means provided in the overall scheduler using the first and second evaluation information. Based on this new constraint condition, each process scheduler creates or corrects a process schedule for its own process.

  Accordingly, a distributed production schedule creation method capable of creating a high-quality schedule in a shorter time as a whole for a production line including a process of batch lots by executing scheduling on each process side and the whole, and That system can be provided.

  According to a second aspect of the present invention, in the production schedule creation system according to the first aspect, the correction processing unit includes a correction determination unit that determines whether or not the process schedule needs to be corrected based on the first and second evaluation information. It is characterized by that. According to this configuration, the correction processing means determines whether or not the process schedule needs to be corrected from the first and second evaluation information. Therefore, since the necessity for correction is determined from the first evaluation information related to each process schedule and the second evaluation information related to the entire schedule, it becomes possible to create a production schedule of higher quality.

  According to a third aspect of the present invention, in the production schedule creation system according to the first or second aspect, the first and second evaluation information is cost information obtained by converting a work time zone into a cost. According to this configuration, the first and second evaluation information includes the work time zone, that is, the time zone determined by any two of the processing start time, the processing end time, and the processing time for the corresponding job. Since the cost information converted into is converted into the same dimension and evaluated, the necessity of correction can be easily determined.

  According to a fourth aspect of the present invention, in the production schedule creation system according to the third aspect, the first and second evaluation information calculating means convert the work time zone in each process according to the weight set for each process. It is characterized by being. According to this configuration, the work time zone in each process is converted according to the weight set for each process by the first and second evaluation information calculation means. This makes it possible to create a production schedule with higher quality.

  According to a fifth aspect of the present invention, in the production schedule creation system according to the third aspect, the first evaluation information includes a value obtained by converting a setup change time required between successive successive processes into a cost. . According to this configuration, since the first evaluation information includes a value obtained by converting the time required for the setup change between successive preceding and subsequent processes into a cost, a production schedule is created in a form that is realistic.

  According to a sixth aspect of the present invention, in the production schedule creation system according to any one of the first to fifth aspects, the overall scheduler includes the created process schedules and the first and second evaluation information of the process schedules. From each process schedule and storage judgment means for judging whether or not each process schedule is temporarily stored in a storage unit, and the correction processing means determines that the created overall schedule needs to be corrected. In this case, when it is determined that the entire schedule is stored in the storage unit, a new constraint condition is created using the first and second evaluation information corresponding to the entire schedule, When it is determined that the schedule is not stored in the storage unit, according to a predetermined rule from the entire schedule already stored in the storage unit The first corresponds to the-option has been one of the entire schedule, using the second evaluation information, characterized in that to create a new constraint.

  According to this configuration, each process schedule and each process schedule are provisionally stored from the created process schedules and the first and second evaluation information of each process schedule by the storage determination unit of the overall scheduler. It is determined whether or not to store in the section. In this case, the storage unit may be provided in the overall scheduler. Alternatively, the process schedule may be stored in each process scheduler, and the overall schedule may be stored in the overall scheduler. Then, if it is determined by the correction processing means that the created overall schedule needs to be corrected, if the storage determining means determines that the entire schedule is stored in the storage unit, this correction corresponds to the entire schedule. When a new constraint condition is created using the first and second evaluation information, and when it is determined that the entire schedule is not stored in the storage unit by the storage determination unit, the storage unit A new constraint condition is created using the first and second evaluation information corresponding to one whole schedule selected according to a predetermined rule from the whole schedule already stored in (1). Therefore, for the correction of the entire schedule that is stored in the storage unit as satisfying a temporary condition, a constraint condition for correction is created based on the first and second evaluation information corresponding to the entire schedule. The On the other hand, even if the current overall schedule does not satisfy the temporary condition and is not stored in the storage unit, one overall schedule is selected from the overall schedules already stored in the storage unit, Since new constraint conditions are created using the corresponding first and second evaluation information, the constraint conditions are created every time until the end, and a better quality schedule is created. Therefore, the correction operation is repeated.

  According to a seventh aspect of the present invention, in the production schedule creation system according to the sixth aspect, each of the process schedules in which the storage judgment means creates a value obtained by adding the cost information as the first and second evaluation information first. When it is determined that the cost information added to the total schedule is reduced by a predetermined amount, each created process schedule, the entire schedule, and each cost information are stored in the storage unit. According to this configuration, the value obtained by adding both the cost information as the first and second evaluation information is a predetermined amount, for example, a predetermined ratio, than the cost information obtained by adding each process schedule and the entire schedule created first. Alternatively, when it is determined that the value has been reduced by a predetermined value, the created process schedule, overall schedule, and cost information are stored in the storage unit. Therefore, it is possible to capture a schedule with a certain quality as a storage target in the storage unit, and a high-quality schedule is finally secured as a selection target.

  According to an eighth aspect of the present invention, in the production schedule creation system according to any one of the first to seventh aspects, the correction processing means is provided in the overall scheduler, and a plurality of pieces of information are generated using the first and second evaluation information. Schedule correction instruction creation means for creating processing instruction priority information for each job of the product as correction instruction contents, and each process scheduler provided with the processing order and lot summary of the product in its own process based on the correction instruction contents And a constraint condition creating means for determining a constraint condition regarding the change of the combination. According to this configuration, the schedule modification instruction creation means on the overall scheduler side creates the priority information of the processing order for each job of a plurality of products as the modification instruction contents using the first and second evaluation information. The restriction condition creating means of the scheduler determines the restriction condition regarding the change of the combination of the product processing order and the lot summary in its own process based on the contents of the correction instruction. Therefore, creation of instruction content for evaluation and correction including evaluation of the entire schedule, and creation of constraint conditions for each process scheduler to create a specific process schedule based on this correction instruction content Therefore, it is expected that the schedule will be revised with good quality in consideration of both overall observation and individual correspondence.

  According to a ninth aspect of the present invention, in the production schedule creation system according to any one of the first to eighth aspects, the correction processing means is configured such that the information on the entire schedule stored in the storage unit satisfies a predetermined end condition. If there is an end determination means for determining that the correction process for each process schedule and the entire schedule is complete, and if the determination result of the end determination means is affirmative, the information on the entire schedule stored in the storage unit One overall schedule is selected, and each process schedule that is the basis of the entire schedule is output to each process scheduler. According to this configuration, when the information regarding the overall schedule stored in the storage unit satisfies the predetermined termination condition, the process for determining each process schedule and the overall schedule is determined to be terminated by the termination determination unit. When the determination result of the end determination means is affirmative, one overall schedule is selected from the information regarding the overall schedule stored in the storage unit, and each process schedule that is the basis of the entire schedule is each process. It is output to the scheduler and set.

  The invention according to claim 10 is an input unit capable of inputting a predetermined end condition after the first first and second evaluation information are calculated in the production schedule creation system according to any one of claims 1 to 9. It is characterized by providing. According to this configuration, the predetermined end condition can be input after the first first and second evaluation information are calculated by the input unit. Therefore, the operator can also set a suitable end condition based on the initial evaluation content.

  According to the inventions described in claims 1 and 11, since the scheduling is executed by each process side and the whole, a schedule having a good quality as a whole can be made in a shorter time for the production line including the process of batch lotting. It is possible to provide a distributed production schedule creation method and system that can be created in

  According to the invention described in claim 2, since the necessity of correction is determined from the first evaluation information related to each process schedule and the second evaluation information related to the entire schedule, a higher quality production schedule is created. It becomes possible to do.

  According to the invention described in claim 3, since the first and second evaluation information is converted into the same dimension as the cost information obtained by converting the work time zone into the cost, the evaluation is made. It can be done easily.

  According to the invention described in claim 4, since the work time zone in each process is converted according to the weight set for each process by the first and second evaluation information calculation means, the quality of work contents Therefore, it is possible to create a better production schedule.

  According to the fifth aspect of the present invention, the first evaluation information includes the value obtained by converting the time required for the setup change between the successive preceding and subsequent processes into the cost. Can be created.

  According to the sixth aspect of the present invention, the correction of the entire schedule that is stored in the storage unit as satisfying a temporary condition is corrected based on the first and second evaluation information corresponding to the entire schedule. On the other hand, even if it is assumed that the current overall schedule does not satisfy the temporary condition and is not stored in the storage unit, the entire schedule already stored in the storage unit Since one whole schedule is selected and a new constraint condition is created using the corresponding first and second evaluation information, the constraint condition can be created every time until the end is reached. This makes it possible to create a better quality schedule.

  According to the seventh aspect of the present invention, a value obtained by adding the cost information as the first and second evaluation information is a predetermined amount from the cost information obtained by adding each process schedule and the entire schedule created first, for example, When it is determined that the predetermined ratio or the predetermined value has been reduced, the created process schedule, overall schedule, and cost information are stored in the storage unit. It is possible to capture, and it is possible to secure a high quality schedule as a final selection target.

  According to the eighth aspect of the present invention, the schedule modification instruction creation means on the overall scheduler side creates the priority information of the processing order for each job of a plurality of products as the modification instruction contents by using the first and second evaluation information. In addition, since the constraint condition creating means of each process scheduler determines the constraint condition regarding the change in the combination of the product processing order and lot summary in its own process based on the contents of the correction instruction, the viewpoint of the entire schedule can be obtained. The entire contents are created by creating the instruction contents to be modified after receiving the evaluation, and by making each process scheduler create a constraint condition for creating a specific process schedule in response to the contents of the modification instruction. It can be expected that the schedule will be revised to a good quality, taking into account both the individual and individual correspondence.

  According to the ninth aspect of the present invention, when the information regarding the overall schedule stored in the storage unit satisfies a predetermined termination condition by the termination determination means, the process of correcting each process schedule and the entire schedule is terminated. When the determination result of the end determination means is affirmed, one overall schedule is selected from the information on the entire schedule stored in the storage unit, and each process schedule that is the source is selected for each Since the information is output to the process scheduler, a high-quality process schedule can be finally set in each process scheduler.

  According to the tenth aspect of the present invention, since the predetermined end condition can be input after the first first and second evaluation information is calculated by the input unit, the operator can perform the operation based on the first evaluation content. A suitable end condition can be set.

  FIG. 1 is an overall schematic configuration diagram showing an example of a production facility provided with a work schedule creation system to which the present invention is applied. The production facility according to the present embodiment includes each facility of step 1 to step 4, a production line that processes products in the order of the steps, process schedulers 11 to 14 provided corresponding to each step, and each step. The entire scheduler 20 can communicate with the schedulers 11 to 14.

  The production line includes a line that produces, manufactures, and processes various ordered products. Here, equipment for manufacturing copper plates is assumed, and it includes four processes including an ingot forming process and a batch annealing process. This mode is assumed. This production line is capable of producing a plurality of types of products, and in each step, at least one step, in this embodiment, all types of products can be processed all at once. It can be handled as a so-called lot summary.

  Each of the process schedulers 11 to 14 is a combination of a processing order and a lot summary for each product (ordered product) in its own process, a processing unit that creates a production schedule that determines at least each work time zone, and an evaluation of the created process schedule. The processing part to perform is provided and details are mentioned later. The overall scheduler 20 includes a processing unit that creates an overall schedule over all processes based on the process schedules created by the process schedulers 11 to 14, a processing unit that evaluates the created overall schedule, and a process based on the evaluation result. At least a processing unit for instructing is provided.

  FIG. 2 is a block diagram illustrating one embodiment of a process scheduler. Since the process schedulers 11 to 14 have the same configuration, the process scheduler 11 will be described as a representative here.

  The process scheduler 11 is preferably composed of a microcomputer that is operated by a processing program, and includes a scheduling constraint creation unit 111, a process schedule creation unit 112, a process schedule storage unit 113, a process cost simulation unit 114, and an overall scheduler 20. The communication part 115 which transmits / receives required information between is provided.

  First, an example of various conditions of work contents for a production target product described below will be described using a table. Table 1 shows lot grouping conditions (combination candidates capable of lot grouping).

  As shown in Table 1, here, it is assumed that six types of orders of products A to F are produced in steps 1 to 4. In step 1, products (A and B), products (C and D), and products (E and F) can be processed as a lot. In step 2, each is processed independently. In step 3, products (A, B, E, and F) and products (C and D) can be processed as a lot. In step 4, the products (A, C, E, and F) and the products (B and D) can be processed as a lot summary.

  Table 2 shows an example of the setup change condition. The condition of the setup change is related to the product to be processed immediately after the product processed immediately before in the same process, and the change of the processing condition or the washing operation of the chemical used for the immediately previous processing at the same equipment is added. This is related to whether or not work is required. In Table 2, ○ indicates that no setup change is required, and x indicates that setup change is required.

  In Table 2, for example, in step 1, when the immediately preceding process is the product B, the product A can be scheduled for the immediately following process. However, when the immediately preceding process is the product C, the immediately following process is performed. Product A cannot be scheduled. Further, in step 4, when the immediately preceding process is the product A, the product C can be scheduled for the immediately following process, but when the immediately preceding process is the product B, the product C is included in the immediately following process. Cannot be scheduled. The time required for the setup change can be set for each process and for each product. However, for convenience of explanation, a uniform predetermined time, for example, 10 minutes is used here. In addition, Table 2 shows whether lots can be grouped from another viewpoint. Therefore, Table 2 is consistent with Table 1.

  Table 3 shows an example of processing time in each process.

  In Table 3, it is 20 minutes, 30 minutes, and 20 minutes for all products in Step 1, Step 3, and Step 4, and in Step 2, each product is different.

  Returning to FIG. 2, the scheduling constraint creation unit 111 creates a constraint condition corresponding to a modification instruction from a schedule modification instruction creation unit 207 described later of the overall scheduler 20. When creating the first schedule (initial schedule), the scheduling constraint creation unit 111 is a constraint condition only for the lot summarization and the processing order of each lot based on Table 1 to be described later. A new constraint condition corresponding to the correction instruction from the schedule correction instruction generation unit 207 is generated.

  The process schedule creation unit 112 satisfies the constraint conditions created by the scheduling constraint creation unit 111, and the schedule schedule is set so that the cost (process cost) described later as the evaluation information regarding the work procedure efficiency in the own process becomes the lowest. Create.

  Here, the process cost refers to a setup change cost required when setup change occurs, and a lot summarization cost that accompanies a single process in the lot summarization process. The lot summarization cost is fixed regardless of the number of lots processed at one time. Further, although the cost may be weighted (a weighting coefficient is given) for each type of cost and process, it is assumed here to be constant. When there is a so-called neck process that has a high influence on other processes, a predetermined weight coefficient may be set for the neck process.

  The process schedule creation unit 112 creates an initial, that is, initial schedule. Specifically, the creation of the initial schedule is performed by batch processing within a combination range so as to minimize the process cost in its own process. And the lot processing order is determined.

  As a schedule creation method, a combination optimization algorithm such as SA (Simulated Annealing) method, GA (Genetic Algorithm) method, MLS (Multi Start Local Search) method or the like can be adopted. Since these contents are publicly known, they will be briefly described below. The SA method expresses a schedule by a combination of a machine that processes a job and a combination of processing order, a processing start time and a processing end time of each job. This method searches for a better combination, that is, a schedule, by changing a part of the combination starting from a randomly generated combination and repeating the evaluation of the changed combination. Normally, when a schedule is evaluated, the schedule is updated only when a better schedule is found. However, in this method, even if the searched schedule is bad with respect to the provisional solution, the probability of updating the schedule is controlled to allow the alteration. The GA method expresses a schedule by a combination of a machine that processes a job and a combination of processing order, a processing start time and a processing end time of each job. In this method, first, a set consisting of a fixed number of solutions called a population, that is, a set made up of schedules, is created and evaluated. After that, two schedules with good evaluation are selected at random, and a new schedule is created by exchanging a part of each schedule. Repeat this to create a certain number of schedules and update the population. These processes are repeated to create a schedule as a group. In the MLS method, a schedule is expressed by a combination of a machine that processes a job and a combination of processing order, a processing start time and a processing end time of each job. This method searches for a better combination, that is, a schedule, by changing a part of the combination as a starting point of the combination created at random and repeating the evaluation of the changed combination. When a schedule is evaluated, the schedule is updated only when a better schedule is found. If a better schedule is not found, the schedule is temporarily ended and a provisional solution is stored. Thereafter, the starting point is changed for a certain time, and the same processing is repeated. After a certain period of time, select the best provisional solution group stored.

  The process schedule storage unit 113 includes a RAM or the like, and stores the process schedule (initial schedule, second and subsequent process schedules) created by the process schedule creation unit 112. The process cost simulation unit 114 calculates a process cost in its own process. Since there is no correction instruction from the overall scheduler 20 when the initial schedule is created, there is no restriction condition for correction, and in principle, the process cost in the own process is set to zero. On the other hand, when the process schedule is corrected in accordance with a correction instruction from the overall scheduler 20, that is, under a new constraint condition, there is a possibility that a process cost may occur in comparison with the initial schedule as will be described later. . The communication unit 115 transmits and receives information to and from the communication unit 208 of the overall scheduler 20. Information transmitted from each process scheduler 11 to 14 to the overall scheduler 20 includes a combination of jobs in each lot (lot summary), a lot processing order, each work time zone (width), and a calculated process. Cost information. The work time zone is determined by any two of the processing start time, the processing end time, and the processing time.

  FIG. 3 is a block diagram illustrating an embodiment of the overall scheduler. The overall scheduler 20 includes an overall schedule creation unit 201, an overall cost simulation unit 202, a cost storage unit 203, a schedule update determination unit 204, a provisional schedule storage unit 205, an end determination unit 206, a schedule correction instruction creation unit 207, and a communication unit 208. Is provided. The overall scheduler 20 is preferably composed of a microcomputer, and executes the functions of the overall schedule creation unit 201, the overall cost simulation unit 202, the schedule update determination unit 204, the end determination unit 207, and the schedule correction instruction creation unit 207. In addition, a ROM for storing a processing program for schedule processing, evaluation, determination, and correction instruction, and initial data necessary for the processing, which controls the processing procedure of each functional unit, is provided. In the form in which the processing program or the like is installed from the external memory, the RAM may be provided, the processing program or the like may be taken into the predetermined area, and another partial area may be used as a work area. The same applies to the process schedulers 11 to 14. Note that the data in Tables 1 to 5 are stored at appropriate positions in a predetermined storage unit of the overall scheduler 20 or taken from an external memory, and are sent to the overall scheduler 20 as needed, and to each process scheduler 11 to 14. To be used.

  The overall schedule creation unit 201 determines the creation of the overall schedule, that is, here the process start time of the lot of each process, from the process schedules from the process schedulers 11 to 14 obtained via the communication unit 208. . The processing start time is the larger of the times when all the jobs included in the lot in the immediately preceding process are completed and (the processing end time of the immediately preceding lot in the own process + the time required for the necessary setup change). is there. In step 1, the processing end time in the previous step is given in advance as the time when the raw materials arrive, the time when all necessary parts are available, etc., but in this embodiment, it is treated as 0 for convenience. Here, the processing end time is a time obtained by processing start time + processing time determined by the combination of the corresponding equipment and product.

  FIG. 5 is a diagram showing an example of the initial schedule created by the overall scheduler and the delivery date of each order based on Table 4. As shown in FIG. 5, in the initial schedule, each process scheduler 11 to 14 considers only the convenience of its own process, and as a result, a setup change has not occurred, and the number of processes in each process is Although it is the minimum, the schedule has been extended, and many delivery delays have occurred. Other than products A and C, there is a delay in delivery date. For example, product B has a delivery time of 110 minutes, but according to the result of this initial schedule, the product completion time is 220 minutes, It is late to. The unit of time for delivery is not limited to “minutes”, but here, for convenience of explanation, “minutes” is assumed.

  The overall cost simulation unit 202 calculates a delivery delay cost for each product based on the overall schedule created by the overall schedule creation unit 201. In this embodiment, the delivery delay cost is calculated with a penalty coefficient for delivery delay per unit time × Max (processing end time in final process—delivery time, 0) for each product. Max (a, b) represents an operator whose solution is the larger value.

  Table 4 shows an example of a penalty coefficient for the delivery date of each product and the delivery time delay per unit time.

  In Table 4, for example, for product C, the penalty coefficient for the delivery delay per unit time is the value 1, while for product A, the penalty coefficient for the delivery delay per unit time is the coefficient 6, which is the highest.

For the initial overall schedule shown in FIG.
Product A: 6 × Max (180−180, 0) = 0
Product B: 3 × Max (220−110, 0) = 330
Product C: 1 × Max (180−200, 0) = 0
Product D: 3 × Max (220−130, 0) = 270
Product E: 2 × Max (200−160, 0) = 80
Product F: 4 × Max (200−170, 0) = 120
Total late delivery cost = 800
It becomes. In a mode in which a weight related to cost (here, a value of 1 is taken into account for convenience), a product of the weight and the total delivery delay cost 800 is the total delivery delay cost value to be output. As can be seen from the above calculation results, in this example, the delivery delay cost for the product B is the largest. A value 800 obtained by adding the cost of each process and the delivery delay cost is the total cost of the schedule.

  The cost storage unit 203 adds the cost of each process (first evaluation information) calculated by the process schedulers 11 to 14 and the delivery delay cost calculated by the overall cost simulation unit 202 (second evaluation information). Here, the value 800 is stored.

  The schedule update determination unit 204 unconditionally captures the initial schedule into the provisional schedule storage unit 205, while regarding the entire schedule created in the second and subsequent times, the total cost of the entire schedule is considered and a predetermined condition is satisfied. If it is determined, the entire schedule is taken into the provisional schedule storage unit 205 as a provisional schedule, whereas if it is determined that the condition is not satisfied, it is not taken in. In the present embodiment, the condition for capturing the entire schedule is when the overall cost is low compared to the total costs of one or more provisional schedules (including the initial schedule) already captured in the provisional schedule storage unit 205. is there. Various conditions can be set as the conditions for updating the entire schedule. For example, in addition to the above conditions or independently, the maximum value of the delayed delivery costs is the maximum of the delayed delivery costs of the provisional schedule. It may be determined whether the total schedule has been created a predetermined number of times, for example, when it has decreased by a predetermined ratio or less than the value or by a condition other than cost. Further, it may be compared with the total cost of the entire schedule corresponding to the initial schedule.

  The provisional schedule storage unit 205 receives an update instruction from the schedule update determination unit 204 and corresponds to the entire schedule, lot summary (combination of lots) in each process, lot processing order, and work time zone (processing for each lot) Information such as a start time, a process end time, and a processing time). The entire schedule to be updated is stored in association with the corresponding cost information.

  The end determination unit 206 receives the initial schedule after the total cost of the new overall schedule is a predetermined amount of the total cost of the initial schedule, specifically, a predetermined value or less, or a predetermined ratio, for example, 30% or less. The schedule correction instruction is terminated when there is. For example, when the total cost of the initial schedule is the value 800 in the above example, the total cost is 30% or less, that is, 560 or less is created and written to the provisional schedule storage unit 205. is there. The end condition is not limited to this, and may be a case where the number of corrections reaches a predetermined number or a case where a corrected schedule is taken into the provisional schedule storage unit 205.

  In a mode in which the schedule correction instruction creating unit 207 performs the schedule correction only a preset number of times, when the schedule update determination unit 204 determines that the condition is satisfied, until the set number of times is reached, A schedule correction is instructed and transmitted to each of the process schedulers 11-14. The contents of the schedule correction instruction are as follows. The cost of each process sent from each process scheduler 11 to 14 of this time and the delivery delay cost of each job are compared, and the cause of the most cost is eliminated. It is related to schedule correction. When a schedule correction instruction is given, it is also possible to add a weight to the cost type and the cost for each process to select a cost or process to be eliminated intensively. In the example of FIG. 5, the increase factor of the total cost is the delayed delivery cost (330) of the product B. Accordingly, the schedule correction instruction creating unit 207 transmits an instruction for each process to formulate a schedule for eliminating the delay in delivery of the product B to each process scheduler 11 to 14. Specifically, for example, the content is “accelerate the job processing order for the product B”.

  On the other hand, when the schedule update determination unit 204 determines that the condition is not satisfied, the schedule correction instruction creation unit 207 receives a signal to that effect and stores the signal in the cost storage unit 203 and the provisional schedule storage unit 205. From each correction schedule, a correction schedule having the maximum overall cost or the maximum delivery delay cost is extracted, and the contents of the schedule correction instruction are created from the correction schedule in the same manner as described above. It is made to transmit to 11-14.

  Here, post-processing will be described in the case where a correction instruction “make the job processing order for product B faster” is created for the initial schedule shown in FIG.

  When the correction instruction is transmitted to each of the process schedulers 11 to 14, the scheduling constraint creating unit 111 (to 141: not shown) of each of the process schedulers 11 to 14 creates a constraint condition from the content of the received correction instruction. .

  The scheduling constraint creating unit 111 (˜141: not shown) of each of the process schedulers 11 to 14 “stores the job processing order for the product B in the process schedule storage unit 113 (˜143: not shown). Create a constraint that “must be earlier than the order”. In the present embodiment, more specifically, for example, the process order of the job of the product B is first in the process 1, the first or second in the process 2, the first in the process 3, and the first or second in the process 4. A constraint is created to process the second. Note that the processing order is fixed to the first for the job processed first at the time of creating the initial schedule.

  And each process schedule preparation part 112 (-142: not shown) uses the above-mentioned schedule preparation method, and observes the said restrictions regarding the job of the goods B, and sets the process schedule which minimizes cost. create.

  FIG. 6 is a diagram illustrating an example of an overall schedule obtained by correcting the overall schedule of FIG. 5 once. As shown in FIG. 6, in the entire schedule corrected once, the jobs of the product B are ordered first in each process. In step 2, the job order of product A and product B is reversed. In step 3, the job of the product B is given priority (the lot summary with the product A is canceled), and the product A is combined with the products E and F and the lot summary. In step 4, as in step 3, the job of product B is first given priority (the lot summary with product D is eliminated), and product D is processed alone. Note that, in step 3, after the processing of the product B, the setup change necessary to perform the processing of the products A and C occurs immediately after the processing of the product B.

  The process cost simulation unit 113 (˜143: not shown) calculates the cost for each process in the process schedule of FIG.

  Table 5 shows an example of the characteristic parameter of each process.

Using Table 5,
(Process 1)
Setup cost: 10 × 0 = 0
Processing cost: 15 × 3−15 × 3 = 0
Therefore, process cost = 0
(Process 2)
Setup cost: 30 × 0 = 0
Processing cost: 10 × 6−10 × 6 = 0
Therefore, process cost = 0
(Process 3)
Setup cost: 40 × 0 = 0
Processing cost: 40 × 3−40 × 3 = 0
Therefore, process cost = 0
(Process 4)
Setup cost: 20 x 1 = 20
Processing cost: 70 × 4-70 × 3 = 70
Therefore, process cost = 90.

  From the above, it can be seen that the process cost in the process 4 is increased by 90 in order to speed up the job processing order of the product B, and the total process cost is 90 in all processes. In step 4, the setup change cost is for product B and is calculated with reference to Table 5, and the processing cost is 3 jobs in the initial schedule, but 4 in process 4. Since it is a job of times, it is calculated with reference to Table 5. That is, when considering the processing cost, the cost for the minimum required number of processing times determined from Table 4 is subtracted.

The overall schedule creation unit 201 creates an overall schedule from the corrected process schedules shown in FIG. 6 received from the process schedulers 11 to 14. With respect to the initial schedule shown in FIG.
Product A: 6 × Max (180−180, 0) = 0
Product B: 3 × Max (100−110, 0) = 0
Product C: 1 × Max (180−200, 0) = 0
Product D: 3 × Max (220−130, 0) = 270
Product E: 2 × Max (200−160, 0) = 80
Product F: 4 × Max (200−170, 0) = 120
Total late delivery cost = 420
It becomes. As shown in the above calculation value, in the initial schedule, the product B, whose delivery delay was the value 330, was corrected by the constraint condition, the delivery delay was the value 0, and the delivery delay was completely eliminated. ing.

  The total cost of the schedule is a value 510 obtained by adding the total process cost 90, which is the total cost of each process, and the current delivery delay cost 420. On the other hand, since the total cost of the initial schedule is the value 800 as described above, the correction schedule at this time is the correction schedule stored in the temporary schedule storage unit 205 most recently (in the case of the first correction, Since the total cost is lower than that of the initial schedule, the schedule update determination unit 204 determines that the update is performed and stores the update in the provisional schedule storage unit 205.

  Further, when it is determined by the end determination unit 206 that the conditions for the end determination have not been reached, the schedule correction instruction creating unit 207 determines each product of the entire schedule written in the current schedule, that is, the provisional schedule storage unit 205. A correction instruction is created from the late delivery cost. In the above example, for example, “Delay delivery delay of product D is further reduced”.

  On the other hand, when the schedule update determination unit 204 determines not to update, the current modified overall schedule is deleted, and the end determination unit 206 determines that the end determination condition has not been reached. The schedule correction instruction creating unit 207 identifies an overall schedule from which a correction instruction is created by a predetermined method from one or a plurality of entire schedules (including the initial schedule) already captured in the provisional schedule storage unit 205 Then, the contents of the correction instruction are created in consideration of the delivery delay cost of each product stored in the cost storage unit 203 corresponding to the specified overall schedule. The predetermined method for specifying the entire schedule from which the correction instruction is generated is, for example, the one with the largest total delivery delay cost in each overall schedule, or the total delivery delay cost of the entire schedule and each process that is the source thereof This is a method of selecting the schedule with the maximum total cost of the total process cost, which is the total of the costs.

  The end determination unit 206 receives the modified entire schedule, and determines whether or not it has ended when cost information of the entire schedule is acquired. The end condition is whether or not the total cost of the modified overall schedule can be reduced by a predetermined ratio or less, for example, 30% or more (becomes 70% or less) with respect to the total cost of the initial schedule. For example, in the case of the above specific example, the total cost of the initial schedule is the value 800, and the total cost of the first correction schedule is the value 510. Therefore, this value 510 is 70% of the value 800 (that is, the value 560). ) It is as follows. Therefore, in this example, the process ends with the first correction.

  Note that the termination condition is not limited to the ratio of the total cost, and may be whether or not the total cost is reduced by a predetermined value or more. It is also good when it happens. Further, the end condition may be set by the number of correction schedules taken into the provisional schedule storage unit 205, or the above-described various conditions may be comprehensively performed.

  FIG. 7 is a diagram illustrating an example of a final overall schedule after the overall schedule of FIG. 5 is corrected several times. In this example, the correction instruction is “to further reduce the delivery delay of the product D” following FIG. 6 (or after the correction is made several times). As shown in FIG. 7, the setup change occurs at three places, but the processing order of the product D is advanced in comparison with FIGS. 5 and 6 in steps 2 to 3. As a result, there is a slight delay in the delivery time of the product B. However, by processing the products B and D together in lots in the process 4, from the value 70 which is the processing cost per time shown in Table 5. In this case, the overall cost is suppressed compared to the overall schedule of FIG.

  FIG. 4 is a diagram showing a processing flow for explaining the relationship between the process scheduler and the overall scheduler. Upon receiving orders for various products, order information necessary for a production schedule such as order quantity and delivery date is obtained and transmitted from the overall scheduler 20 to each process scheduler, thereby starting this processing flow. First, each process scheduler 11 to 14 creates a process schedule for the convenience of each process, and each created process schedule is transmitted to the overall scheduler 20 to create an overall schedule. That is, an initial schedule is created (step S1, for example, see FIG. 5). Then, evaluation information related to the evaluation of the work procedure efficiency of the creation schedule such as the process cost of each process schedule and the delivery delay cost of the entire schedule is converted into cost information and calculated. The cost information of the created entire schedule is evaluated, a correction instruction for the first correction is generated, and transmitted to each process scheduler 11 to 14 (step S2). Each process scheduler 11-14 creates a constraint condition and reschedules its own process schedule (see step S4, for example, FIG. 6). Next, as described above, the process cost, the delivery delay cost, and the like are calculated, and based on this, the suitability of the correction schedule (necessity of correction, whether update is possible) is determined (step S4). Subsequently, it is determined whether or not the end condition is satisfied (step S5). If the end condition is satisfied, this flow is ended. On the other hand, if the end condition is not satisfied, a correction instruction is generated, the process returns to step S2, and until the end condition is satisfied (for example, see FIG. 7), the schedule is corrected (NO in steps S2 to S4 and step S5). repeat.

  Note that the types of products and the number of work processes are not limited to those in the present embodiment, and can be variously set corresponding to each facility constituting the production line.

It is a whole schematic block diagram which shows an example of the production facility provided with the work schedule preparation system to which this invention is applied. It is a block diagram which shows one Embodiment of a process scheduler. It is a block diagram which shows one Embodiment of a whole scheduler. It is a figure which shows the processing flow for demonstrating the relationship of the process of a process scheduler and a whole scheduler. It is a figure which shows an example of the initial schedule which the whole scheduler produced, and the delivery date of each order based on Table 4. FIG. It is a figure which shows an example of the whole schedule which corrected the whole schedule of FIG. 5 once. It is a figure which shows an example of the last whole schedule after correcting the whole schedule of FIG. 5 several times.

Explanation of symbols

11-14 Process scheduler 111 Scheduling constraint creation unit (correction processing means)
112 process schedule creation unit 113 process schedule storage unit (storage unit)
114 process cost simulation unit 115 communication unit 20 overall scheduler 201 overall schedule creation unit 202 overall cost simulation unit 203 cost storage unit (storage unit)
204 Schedule update determination unit (correction processing means)
205 Provisional schedule storage unit (storage unit)
206 End determination unit (correction processing means)
207 Schedule correction instruction creation unit (correction processing means)
208 Communication Department

Claims (11)

A production schedule creation system for creating a production schedule for producing a plurality of types of products by performing batch summarization in any one of a plurality of processes,
A process scheduler that is provided for each process and creates a process schedule for its own process;
An overall scheduler that is communicably connected to each process scheduler and creates an overall schedule based on the process schedule created by each process scheduler;
Each of the process schedulers is provided with a process schedule creating means for creating a process schedule of the own process based on a processing order for each product set for the own process, a combination of lots and a predetermined constraint condition;
Provided with at least one of the process scheduler and the overall scheduler, and includes first evaluation information calculation means for calculating first evaluation information relating to work procedure efficiency of the created process schedule, and
The overall scheduler is
An overall schedule creation means for creating an overall schedule for all processes based on each process schedule;
Second evaluation information means for calculating second evaluation information related to work procedure efficiency of the created overall schedule;
A production schedule creation system comprising: correction processing means for creating a new constraint condition for correcting each process schedule by the process scheduler using the first and second evaluation information.   2. The production schedule creation system according to claim 1, wherein the correction processing means includes a correction determination means for determining whether or not the process schedule needs to be corrected based on the first and second evaluation information.   The production schedule creation system according to claim 1 or 2, wherein the first and second evaluation information is cost information obtained by converting a work time zone into a cost.   4. The production schedule creation system according to claim 3, wherein the first and second evaluation information calculation means convert a work time zone in each process according to a weight set for each process.   4. The production schedule creation system according to claim 3, wherein the first evaluation information includes a value obtained by converting a time required for setup change between successive preceding and following processes into a cost.   The overall scheduler determines whether or not to temporarily store each process schedule and each process schedule in the storage unit from each created process schedule and the first and second evaluation information of each process schedule. A storage determination unit, and when the correction processing unit determines that the created overall schedule needs to be corrected, if the entire schedule is determined to be stored in the storage unit, it corresponds to the entire schedule. The first and second evaluation information is used to create a new constraint condition. On the other hand, when it is determined that the entire schedule is not stored in the storage unit, the whole already stored in the storage unit A new constraint condition is created using the first and second evaluation information corresponding to one entire schedule selected according to a predetermined rule from the schedule. Production scheduling system according to any one of claims 1 to 5, characterized in that the.   When the storage judging means judges that the value obtained by adding the cost information as the first and second evaluation information is reduced by a predetermined amount from the cost information added to each process schedule and the entire schedule created first. The production schedule creation system according to claim 6, wherein the created process schedules, overall schedules, and cost information are stored in the storage unit.   The correction processing means is provided in the overall scheduler, and uses the first and second evaluation information to create priority information of processing order for each job of a plurality of products as correction instruction contents, A constraint condition creating unit that is provided in each process scheduler and that determines a constraint condition related to a change in a combination of a processing order of products and a combination of lots based on the correction instruction content. Item 8. The production schedule creation system according to any one of Items 1 to 7.   The correction processing means includes an end determination means for determining that the correction process for each process schedule and the entire schedule is ended when the information on the entire schedule stored in the storage unit satisfies a predetermined end condition. When the determination result of the determination means is affirmative, one overall schedule is selected from information related to the entire schedule stored in the storage unit, and each process schedule that is the source is output to each process scheduler The production schedule creation system according to claim 1, wherein:   The production schedule creation system according to claim 1, further comprising an input unit capable of inputting a predetermined end condition after the first first and second evaluation information are calculated. A process scheduler that is provided for each process and creates a process schedule for its own process;
It is connected to each process scheduler so as to be communicable, and has an overall scheduler that creates an overall schedule based on the process schedule created by each process scheduler, so that lots can be collected in one of a plurality of processes. A production schedule method for creating a production schedule for producing a plurality of types of products,
The process schedule creation means provided in each of the process schedulers creates a process schedule for the own process based on the processing order for each product set for the own process, a combination of lots and a predetermined constraint condition,
First evaluation information calculation means provided in at least one of the process scheduler and the overall scheduler calculates first evaluation information related to work procedure efficiency of the created process schedule,
An overall schedule creation means provided in the overall scheduler creates an overall schedule over all processes based on each process schedule,
A second evaluation information means provided in the overall scheduler calculates second evaluation information relating to work procedure efficiency of the created overall schedule;
The correction processing means provided in the overall scheduler creates the new constraint condition for correcting each process schedule by the process scheduler using the first and second evaluation information. Production schedule creation method.

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