JPH0581288A - Schedule forming system - Google Patents

Abstract

PURPOSE:To form a practical schedule within a limited time by utilizing a result obtained on the way of calculation in schedule formation for executing the allocation of plural jobs and plural resources under a fixed restriction condition. CONSTITUTION:A restriction checking part 71 in an allocation determining part 7 selects a restriction condition to be satisfied at current time from a restriction condition selector 6, successively searches allocation satisfying all conditions and stores the searched results in an allocation status storing part 72. An allocation status evaluating part 73 occasionally evaluates an allocation midway result at the current time in accordance with the contents of the storing part 72 and stores a more effective allocation state in an allocation history storage device 8. When a schedule is completed under the restriction condition at the current time, an important condition is selected from the selector 6 and added to the schedule to complete schedule formation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a schedule creating method, and more particularly to a schedule creating optimizing method for efficiently allocating a plurality of jobs and a plurality of resources under a certain constraint condition.

[0002]

2. Description of the Related Art Assignment of a plurality of jobs and a plurality of resources under a certain constraint condition is performed by, for example,
It is a work that is routinely performed in various fields such as creating shift work schedules for humans, creating schedules for production processes in factories, creating train schedules, allocating vehicles, and creating delivery plans.

Conventionally, such assignment work has been performed manually by using the know-how of an expert, but in recent years, machine automation has been actively promoted due to the development of computer technology.

Methods for automation include a mathematical programming approach and a knowledge engineering approach. The former is effective only when the format of the constraint condition is prepared, such as when the constraint condition can be described by an equality or an inequality. However,
In practical problems, constraints are often described in multiple formats. So, taking the latter approach as a base,
The method with the addition of a hiluristic is more applicable.

As a known example related to this, for example, Japanese Patent Laid-Open No. 63-163669 discloses a method of allocating from a job having severe constraints.

[0006]

The following processing procedure has been conventionally adopted as a knowledge engineering approach to the problem of schedule creation.

(1) A plurality of jobs are expressed as a frame serving as a schedule unit, and stored in order. (2) Take out the top frame. (3) Extract one resource from a plurality of resources. (4) Check whether the retrieved resource satisfies the constraint condition of allocation. (A) If it matches, the allocation for the frame is determined. (B) If they do not match, the next resource is extracted and the constraint condition is checked. (C) When there are no more resources to be taken out, the processing of the previously processed frame is canceled and the processing of (3) is restarted (backtrack processing). (5) Returning to (2), the next frame allocation process is performed. Furthermore, the processes from (2) to (5) are repeated until there are no unassigned frames.

The method disclosed in Japanese Patent Laid-Open No. 63-163669 is also a schedule creating method based on the above procedure, and the number of assignable resources for each job is adopted as an index showing the degree of severity. However, the jobs with smaller values are assigned first.

However, when this method is applied to schedule creation, since the assignment is made without considering the importance of each constraint condition, there is no guarantee that important constraints are satisfied during the calculation. There is a problem.

In general, when a user describes constraint conditions, it is difficult to determine whether a schedule satisfying all the constraint conditions can be created within a fixed time. Therefore, in order to automatically create a schedule that is strongly constrained by a computer, it is necessary to effectively use the intermediate results of the calculation.

It is an object of the present invention to utilize a mid-calculation result in creating a schedule to realize a practical schedule creation within a fixed time.

[0012]

In order to achieve the above object, the present invention provides a method for automatically creating a schedule by assigning a plurality of jobs and a plurality of resources according to a constraint condition. Set and classify constraint conditions according to importance, increase constraints in order from the highest level, gradually adjust schedule results, and create a schedule that satisfies more constraint conditions within a preset time It was something that I tried to do.

Further, when a result that satisfies all the constraint conditions is not obtained within the set time, the intermediate result is interactively modified to create a practical schedule.

[0014]

In order to effectively use the result of the schedule creation, the level of importance is set for each constraint condition, and resources are allocated to the schedule units as follows.

(1) Set the time used for automatic schedule creation. (2) Select all indispensable constraint conditions and set them as a constraint condition set. (3) Under the constraint condition set, a schedule is created based on a normal knowledge engineering method. In this process, history information is obtained at any time with respect to the calculation result in the state in which the constraint condition is most satisfied. Also, when the time set in (1) is exceeded, the automatic schedule creation process ends. (4) Regarding schedule creation under the constraint condition set, (A) If successful, proceed to (5). (B) If it fails, the process ends. (5) Next, select all constraints with the highest level of importance,
Add to the constraint set. If there are no more constraints to add, the process ends. (6) Return to (3) to create a schedule for the next level.

The schedule calculation result obtained by the above-described processing is an intermediate result that satisfies the constraint condition up to a certain level even if the schedule that satisfies all the conditions cannot be created within the set time. ing. Therefore, if this intermediate result is insufficient, the automatic scheduling is continued after a certain period of time is delimited, or the intermediate result is corrected using the interactive correction function. It is possible to adjust to a regular schedule.

[0017]

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

FIG. 1 is a block diagram of an information processing system for realizing the schedule creating method of the present invention. This system includes a job storage device 1, a resource storage device 2, a constraint condition storage device 3, a job selection device 4, a resource selection device 5, a constraint condition selection device 6, an allocation determination device 7, and an allocation history storage device 8. .. The allocation determination device 7 further includes a constraint condition check unit 71, an allocation status storage unit 72, and an allocation status evaluation unit 73.

The job storage unit 1 stores information for each job as shown in FIG. For example, job number 1, job name A, work time on the morning of the 1st, work staff 3 people, required qualification B level, work content C and location A,
Information such as is recorded.

The resource storage device 2 stores information on each resource as shown in FIG. For example, resource number 1, resource name A, possessed qualifications B and C, possible work A, B, D, time conditions are not specified, and place conditions are A, E, F, etc. Has been done.

The constraint condition storage device 3 stores information on the relationship between jobs and resources as shown in FIG.
For example, information such as constraint condition number 1, the content "at least one person with a qualification B or higher is required for nighttime work", and level of importance 2 is stored.

In the job selection device 4, the job storage device 1
Jobs are read out from each job, each job is expanded into a frame format that is a schedule unit, the selection order of the frames is determined, and the frames are selected one by one.

The resource selection device 5 reads out the resources from the resource storage device 2, expands each resource into a format of a resource unit to be assigned to a frame, determines the selection order of the resource units, and selects the resource units one by one. To do.

The constraint condition selection device 6 reads out the constraint conditions from the constraint condition storage device 3, classifies them according to the importance level, and selects the constraint condition to be satisfied next.

In the allocation determining device 7, first, the constraint condition checking unit 71 selects from the constraint condition selecting device 6 the constraint condition that should be satisfied at the present time and sets it as a constraint condition set. For example, at the start of scheduling creation, only constraint conditions designated as essential conditions are selected. next,
The constraint check unit 71 checks whether or not the job (frame unit) and the resource (resource unit) selected by the job selection device 4 and the resource selection device 5 violate the previously set constraint condition set. When all the constraint conditions are satisfied, allocation is determined and stored in the allocation status storage unit 72. If none of the constraints are met, consider another assignment and find an assignment that satisfies all of the constraints.

The allocation status evaluation unit 73 evaluates the allocation intermediate results of the schedule stored in the status storage unit 72 at any time, and when the allocation status is better than before,
The status is stored in the allocation history storage device 8. At the time of evaluation, the allocation status evaluation unit 73 refers to the allocation history storage device 8.

When all resource units have been allocated, the constraint condition check unit 71 again selects the constraint condition of the next importance level from the constraint condition selection device 6 and sets a new constraint condition set, Run the schedule again. The constraint check unit 71 ends the schedule creation when the constraint condition of the next importance level cannot be selected or the time for creating the schedule is consumed.

The allocation status evaluation unit 73 of the allocation determination unit 7 and the allocation history storage unit 8 store the intermediate results of the schedule creation process, and the introduction of the limited process of the schedule creation time based on the timing function of the constraint condition check unit 71. Is a feature of the present invention.

FIG. 5 is a flow chart showing the overall processing procedure in the allocation determining device 7.

The allocation determining device 7 first designates a time used for creating a schedule (step 501). The constraint condition check unit 71 of the allocation determining apparatus 7 always measures the time taken to create a schedule, and if this time is exceeded, the process ends even if the schedule is being created.

In creating the schedule, the constraint condition check unit 71 selects constraint conditions whose importance level is essential from the constraint condition selection device 6 and sets them as constraint condition sets (step 502). Schedule creation is executed under this constraint condition set (step 503). When the schedule creation is completed (Yes in step 504)
Specifies the constraint condition of the next importance level by the constraint condition selection device 6
(Step 505), add to the current constraint conditions (step 507), and create a schedule under a new constraint condition set (step 503).

On the other hand, if the schedule creation is not completed (No in step 504), it is impossible to create a schedule that satisfies all the conditions under the current constraint set, so interactive correction is made. After performing the process (step 508), the process ends. In this interactive modification process, for the purpose of assisting the modification by the user, display of the best halfway schedule result, display of unsatisfied constraints, display of the effect on the entire schedule for the change of the specified individual allocation, etc. I do.

If there is no constraint condition for the next importance level to be added (Yes in step 506), the complete schedule has been created, and the process is terminated.

FIG. 6 shows a detailed flow chart regarding the schedule creation in step 503 of FIG. The allocation determining device 7 sequentially selects each schedule unit from the job selecting device 4 and the resource selecting device 5 (step 601), and repeats the following processing until there are no candidates to be allocated (Yes in step 602).

First, the constraint check unit 71 of the assignment determining device 7 checks whether all the constraint conditions in the constraint set are satisfied for the selected assignment candidate (step 603), and even one is satisfied. If there is a condition not to do so (No in step 604), the allocation candidate is selected again. If all the constraint conditions are satisfied (Yes in step 604), this allocation candidate is stored in the allocation status storage unit 72 (step 605). The allocation status evaluation unit 73 reads the contents of the allocation status storage unit 72 and evaluates the current schedule creation status (step 606). Then, if the evaluation result is better than the schedule creation status so far (step 607).
If Yes, the current schedule creation status is stored in the allocation history storage device 8 (step 608), and if it is not good (No in step 607), it is left as it is.
Furthermore, if the time used for creating the schedule exceeds the time set at the start, the process ends even while the schedule is being created (Yes in step 609).

[0036]

As is apparent from the above description, according to the present invention, in scheduling in which allocation between a plurality of jobs and a plurality of resources is performed according to a constraint condition, the constraint condition is classified into importance levels, Since the schedules are created in order of importance, the schedule is created by taking a history step by step and limiting the time, so even a schedule result in the middle of calculation will satisfy a certain level of constraint conditions. There is. Therefore, it is possible to create a practical schedule within a limited time by executing automatic schedule creation again based on this result or interactively performing correction processing.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an embodiment of an information processing system that realizes a schedule creation method of the present invention.

FIG. 2 is a diagram showing a specific example of a job.

FIG. 3 is a diagram showing a specific example of resources.

FIG. 4 is a diagram showing a specific example of constraint conditions.

5 is a flowchart of an overall processing procedure in the allocation determining device of FIG.

6 is a detailed flowchart of a schedule creating procedure under a fixed constraint condition set in the allocation determining apparatus of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 job storage device 2 resource storage device 3 constraint condition storage device 4 job selection device 5 resource selection device 6 constraint condition selection device 7 allocation determination device 71 constraint condition check unit 72 allocation status storage unit 73 allocation status evaluation unit 8 allocation history storage device

Claims (2)

[Claims] 1. A method of automatically creating a schedule by allocating a plurality of jobs and a plurality of resources according to a constraint condition, setting a schedule creation time, classifying the constraint condition into levels according to importance, and setting the condition. A schedule creation method characterized in that a schedule is created in such a way that constraints with higher importance are met within the time limit. 2. The schedule creating method according to claim 1, wherein when a result that satisfies all the constraint conditions is not obtained within the set time, the intermediate result is interactively modified to create the schedule.