JPH01240973A - Work allotting system - Google Patents

Abstract

PURPOSE:To prepare a high-quality schedule at high speed and in a stable time by providing a means to evaluate how unpreferable to violate constraint when plural pieces of work is allotted in a lump. CONSTITUTION:A means 101 to divide a schedule period into partial periods, a means 102 to evaluate the desirableness of the combination between the work and a device in the partial period, and a means 103 to synthetically judges the work in the partial period and to calculate the combination to have the maximum evaluation are provided. Thus, by dividing the period into the partial periods in which the work and the device correspond at 1:1, the allotting algorithm of a mathematical plan can be applied, and a solution can be calculated for the schedule having the solution without the constraint violation. When the schedule cannot be obtained without the control condition violation, since the importance of the constraint violation can be evaluated, the schedule can be prepared with the lightest violation and in a range with the smallest violence. Thus, the high-quality schedule can be prepared at high speed and in the stable time.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a computer system that solves various scheduling problems, and in particular, the present invention relates to a computer system that solves various scheduling problems, and in particular, a computer system that solves various scheduling problems. This invention relates to a work allocation method suitable for creating schedules in ambiguous cases.

[Conventional technology]

Scheduling problems are generally problems of permutations and combinations, and are difficult to formulate and solve using mathematical methods. Therefore, conventionally, a method has often been adopted in which, for each target problem, all schedule planning know-how and conditions specific to that problem are programmed and a schedule is created. However, the above method requires a lot of know-how to create schedules.

There is a problem in that it is not possible to respond quickly to changes in conditions. As a method to solve this problem, a method has recently been considered that applies knowledge engineering technology to create a knowledge base of schedule creation know-how and conditions and solve them in a simulation manner so that changes in schedule creation know-how and conditions can be quickly responded to. It is being An example of the above method is the Information Processing Society of Japan
3rd (late 1986) National Conference Lecture Collection H No. 116
It is stated on pages 5 to 1166. in this way.

Works are allocated one by one, and if a constraint violation occurs, a schedule is created without backtracking and avoiding the constraint violation. If a constraint violation cannot be avoided, this is assigned as long as the violation is allowed.

[Problems that the invention attempts to solve]

In a method like the conventional technology mentioned above, which focuses on each work and sequentially allocates the workpieces, when a constraint violation occurs, it is difficult to avoid the violation by backtracking, or whether there is no solution unless it is violated and allocated. , it is difficult to judge. Therefore, there is a problem in that it takes a lot of time to create a schedule due to unnecessary backtracking. In addition, even if assignments are made in violation, it is difficult to judge which constraint conditions should be relaxed, and even if the schedule results in a minor violation overall, it is difficult to determine which constraint conditions should be relaxed. There was a problem with making it. Furthermore, there is a problem in that the calculation time is unstable depending on schedule conditions due to the occurrence of backtracking.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and provide a work allocation method that can create a high-quality schedule quickly and stably.

[Means for solving problems]

The above object is achieved by providing a function that evaluates the importance of violation of constraint conditions and allocates works at once when creating a work schedule.

Specifically, (1) means for dividing the schedule period into partial periods, (2) means for evaluating the desirability of the combination of work and equipment in the partial periods, and (3) means for comprehensively evaluating the work in the partial periods. means for calculating the combination that maximizes the above evaluation.

[Effect]

Said means operate as follows.

By dividing the work into partial periods in which the work and the equipment correspond one-to-one, a mathematical programming assignment algorithm can be applied, and solutions can be calculated for cases where there is a solution without violating any constraints. If a schedule cannot be created without violating a constraint, the importance of the violation of the constraint can be evaluated, so a schedule can be created with as few violations as possible and with as few violations as possible. This allows high-quality schedules to be created quickly and stably.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 6, taking assignment of workpieces to a manufacturing apparatus as an example. FIG. 1 shows the overall configuration of the present invention. 11 is a computer for controlling this system, and includes a partial period determination unit 101. 612 is composed of a work constraint violation importance determination unit 102, an allocation calculation unit 103, and a schedule result display unit 104.
13 is a device for storing schedule target data; 14 is a device for storing schedule planning know-how; A device 16 that stores constraints for creating a schedule is a device that stores schedule results.

Hereinafter, one embodiment of the present invention will be described in detail using the constraints on the operating time of the apparatus as an example, according to the operational steps of the flowchart shown in FIG.

In step 201, the system displays the schedule result stored in the schedule result storage device 16 on the display device, and proceeds to step 2028.

In step 202, the system determines whether schedule creation is complete. If completed, the system is terminated; if not completed, proceed to step 2038.

The step 2o3 system is based on the schedule creation know-how stored in the storage device 14, and determines a period (hereinafter referred to as 5 partial periods) for creating a schedule, for example,
As shown in FIG. 3, a period during which at most one workpiece can be assigned to one manufacturing apparatus is determined. In Figure 3, ]-6
The partial period will be from June 1st to the 18th. Next, the process advances to step 204.

In step 204, the system searches the schedule target data stored in the storage device 14 for a work that can be allocated to a partial period and that should be allocated to one device, and stores it in the work storage table shown in FIG.

Next, the process advances to step 205.

In step 205, the system searches for constraints on schedule creation stored in the storage device 15. Fifth
The figure is an example of a table of constraints regarding the operating time of the device. 501 is the device name, 502 is the device usage record,
503 is a limit value of operating time, and 504 is a limit value when operating beyond the limit value. Next, the process advances to step 206.

Step 206: Based on the constraints searched in step 205, the system determines the importance of violation of constraints on the workpiece. The degree of importance is evaluated in the following order: for example, the work can be allocated within the time limit, the work can be allocated without exceeding the limit value, and the work exceeds the limit value. Next, the process advances to step 207.

Step 207: The system digitizes the importance determined in step 206 and creates a matrix as shown in FIG. In this example, for device a, (1) Work A assigned within the time limit → 10 points (2) Work B assigned beyond the time limit but without exceeding the limit → 7 points (3) The above ( Same as 2), but set the time limit to Work B.
Workpiece C-5 point that exceeds the limit value (4) Workpiece D that exceeds the limit value → point ○. Next, the process proceeds to step 208.

In step 208, the matrix obtained in step 207 is used as a mathematical programming assignment problem to find a combination that maximizes the sum of the values of each element of the matrix. Next, the process returns to step 201.

In the case of this embodiment, when solving as an assignment problem in linear programming, scores are divided according to the degree of violation of the time limit constraint. As a result, when a violation inevitably occurs, work with a minor violation that has a high overall score is assigned. This allows you to create a high-quality and efficient schedule.

Further, the score may be determined as follows, for example. Now, assume that there are constraint conditions A and B. From the perspective of the entire schedule, if two violations of A and one violation of B are equivalent, violation of A: 5 flashing points, violation of B: 10 points will be deducted.

〔Effect of the invention〕

According to the present invention, when creating a schedule, it is possible to comprehensively evaluate the balance of the entire schedule and perform bulk allocation, which reduces the need for backtracking and re-allocation of work such as re-allocation of parts that have already been optimally allocated. , it is possible to create a high-quality schedule. That is, it is possible to reduce the occurrence of violations during schedule creation, and to make the violations that occur less severe.

Furthermore, since backtracking can be suppressed, it is possible to create a high-quality schedule quickly and stably.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing the overall implantation of an embodiment of the present invention, Fig. 2 is a flowchart of a system implementing the present invention, Fig. 3 is an explanatory diagram showing an example of a partial period, and Fig. 4 is a layout diagram. Figure 5 is an explanatory diagram showing an example of a work table. Figure 5 is an explanatory diagram showing an example of a constraint table. Figure 6 is a matrix diagram for calculating allocation. 1 Figure 2 □ ■--■ Figure 3 '44 Mouth S Figure B

Claims (1)

[Claims] 1. In a system that creates various schedules such as work scheduling for production processes, in addition to a means for displaying the created schedule results and a means for storing the schedule results, there are also constraints when allocating multiple workpieces at once. A work allocation method characterized by providing a means for evaluating how bad it is to violate conditions.