PRODUCTION SCHEDULE CREATING APPARATUS, PRODUCTION SCHEDULE CREATING METHOD, AND PRODUCTION SCHEDULE CREATING PROGRAM
20190228360 ยท 2019-07-25
Inventors
Cpc classification
Y02P90/02
GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
Y02P90/30
GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
G05B19/418
PHYSICS
International classification
G06Q10/06
PHYSICS
Abstract
To make it possible to plan and provide a new production schedule reflecting characteristics or tendencies appearing in production schedules planned in the past. A schedule planning section calculates, on the basis of history information concerning production schedules of products planned in the past, a schedule pattern including production order of the products while considering constraint conditions in producing the products, rearranges the production order of the products according to the calculated schedule pattern, and creates a plurality of schedule candidates concerning a production schedule of the products. A schedule evaluating section evaluates the plurality of schedule candidates on the basis of evaluation indicators corresponding to the constraint conditions, and selects a best production schedule out of the plurality of schedule candidates.
Claims
1. A production schedule creating apparatus comprising: a schedule planning section that calculates, on the basis of history information concerning production schedules of products planned in the past, a schedule pattern including production order of the products while considering constraint conditions in producing the products, rearranges the production order of the products according to the schedule pattern, and creates a plurality of schedule candidates concerning a production schedule of the products; and a schedule evaluating section that evaluates the plurality of schedule candidates on the basis of evaluation indicators corresponding to the constraint conditions, and selects a best production schedule out of the plurality of schedule candidates.
2. The production schedule creating apparatus according to claim 1, wherein the schedule planning section creates the plurality of schedule candidates on the basis of weighting corresponding to a probability obtained by applying the schedule pattern to data to be scheduled representing characteristics of products for which a production schedule is newly created, the probability being a transition probability of products to be produced following the products.
3. The production schedule creating apparatus according to claim 2, wherein, when a specific constraint condition that has to be always satisfied is present among the constraint conditions, the schedule planning section creates the plurality of schedule candidates to satisfy the specific constraint condition.
4. The production schedule creating apparatus according to claim 3, wherein the schedule planning section calculates a plurality of evaluation indicator values corresponding to the plurality of schedule candidates on the basis of the evaluation indicators tuned using the history information, and the schedule evaluating section selects, as the best production schedule, a production schedule corresponding to a best evaluation indicator value among the evaluation indicator values of the plurality of schedule candidates.
5. The production schedule creating apparatus according to claim 4, wherein the schedule evaluating section selects, as the best production schedule, a specific schedule candidate having a smallest sum of the evaluation indicator values among the evaluation indicator values of the constraint conditions calculated concerning the plurality of schedule candidates.
6. The production schedule creating apparatus according to claim 1, wherein the schedule evaluating section dynamically tunes the evaluation indicators on the basis of data collected from an external system, evaluates the plurality of schedule candidates on the basis of new evaluation indicators after the tuning, and selects the best production schedule out of the plurality of schedule candidates.
7. The production schedule creating apparatus according to claim 1, wherein the schedule evaluating section repeatedly executes the evaluation based on the evaluation indicators by applying a recursive algorithm to a process up to the selection of the best production schedule.
8. A production schedule creating method in a production schedule creating apparatus that creates a production schedule of produces, the production schedule creating method comprising: a schedule planning step in which the production schedule creating apparatus calculates, on the basis of history information concerning production schedules of products planned in the past, a schedule pattern including production order of the products while considering constraint conditions in producing the products, rearranges the production order of the products according to the schedule pattern, and creates a plurality of schedule candidates concerning a production schedule of the products; and a schedule evaluating step in which the production schedule creating apparatus evaluates the plurality of schedule candidates on the basis of evaluation indicators corresponding to the constraint conditions, and selects a best production schedule out of the plurality of schedule candidates.
9. The production schedule creating method according to claim 8, wherein, in the schedule planning step, the production schedule creating apparatus creates the plurality of schedule candidates on the basis of weighting corresponding to a probability obtained by applying the schedule pattern to data to be scheduled representing characteristics of products for which a production schedule is newly created, the probability being a transition probability of products to be produced following the products.
10. The production schedule creating method according to claim 9, wherein, in the schedule planning step, when a specific constraint condition that has to be always satisfied is present among the constraint conditions, the production schedule creating apparatus creates the plurality of schedule candidates to satisfy the specific constraint condition.
11. The production schedule creating method according to claim 10, wherein in the schedule planning step, the production schedule creating apparatus calculates a plurality of evaluation indicator values corresponding to the plurality of schedule candidates on the basis of the evaluation indicators tuned using the history information, and in the schedule evaluating step, the production schedule creating apparatus selects, as the best production schedule, a production schedule corresponding to a best evaluation indicator value among the evaluation indicator values of the plurality of schedule candidates.
12. The production schedule creating method according to claim 11, wherein, in the schedule evaluating step, the production schedule creating apparatus selects, as the best production schedule, a specific schedule candidate having a smallest sum of the evaluation indicator values among the evaluation indicator values of the constraint conditions calculated concerning the plurality of schedule candidates.
13. The production schedule creating method according to claim 8, wherein, in the schedule evaluating step, the production schedule creating apparatus dynamically tunes the evaluation indicators on the basis of data collected from an external system, evaluates the plurality of schedule candidates on the basis of new evaluation indicators after the tuning, and selects the best production schedule out of the plurality of schedule candidates.
14. The production schedule creating method according to claim 8, wherein, in the schedule evaluating step, the production schedule creating apparatus repeatedly executes the evaluation based on the evaluation indicators by applying a recursive algorithm to a process up to the selection of the best production schedule.
15. A production schedule creating program for causing a computer to execute: a schedule planning step for calculating, on the basis of history information concerning production schedules of products planned in the past, a schedule pattern including production order of the products while considering constraint conditions in producing the products, rearranging the production order of the products according to the schedule pattern, and creating a plurality of schedule candidates concerning a production schedule of the products; and a schedule evaluating step for evaluating the plurality of schedule candidates on the basis of evaluation indicators corresponding to the constraint conditions, and selecting a best production schedule out of the plurality of schedule candidates.
Description
BRIEF DESCRIPTION OF DRAWINGS
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DESCRIPTION OF EMBODIMENTS
[0031] Embodiments of the present invention are explained in detail below with reference to the drawings.
(1) First Embodiment
(1-1) Hardware Configuration
[0032]
[0033] A program 4A, a database 4B, and a tuning parameter 4C are stored in the storage device 4. The database 4B includes a table as explained below. The table is referred to and updated by the program 4A.
(1-2) Software Configuration
[0034]
[0035] In the schedule history storage DB 11, schedules planned in the past are stored as schedule histories 11A, 11B, and 11C together with information such as planners and planning periods (see
[0036] The machine learning section 12 has a function of reading, from the schedule history storage DB 14, the schedule histories 11A, 11B, and 11C in a predetermined unit, that is, for example, for each planner and for each schedule period and outputting a schedule pattern according to machine learning.
[0037] The machine learning section 12 has a function of, as preprocessing, converting the schedule histories 11A, 11B, and 11C into a machine-learnable data format and creating teacher data. A conversion method into the teacher data is explained below.
[0038] The machine learning section 12 has a function of, in parallel to the processing explained above, a function of determining a parameter of an evaluation indicator (hereinafter referred to as evaluation indicator parameter) on the basis of the read schedule histories 11A, 11B, and 11C. Note that, in this embodiment, the evaluation indicator is referred to as KPI as well.
[0039] Specifically, first, the machine learning section 12 reads constraint conditions 13 and calculates a frequency of violation of the constraint conditions 13 (hereinafter referred to as violation frequency) and a maximum value of a violation amount representing whether the constraint conditions 13 are violated. Note that the violation frequency referred to herein means a frequency represented by the number of violations of the constraint conditions 13/the number of violations of all constraint conditions. Further, the machine learning section 12 determines evaluation indicator parameters on the basis of the violation frequency and the maximum value. The machine learning section 12 stores the parameters in the machine learning result storage DB 14 while linking the parameters with a schedule pattern obtained by learning schedule histories in the past in that way. Details of the machine learning section 12 are explained below.
[0040] The schedule planning section 15 has a function of applying the schedule pattern to input data to be scheduled, that is, data for which a schedule is newly planned to, as explained in detail below, calculate a transition probability of other products that could be arranged following the products and create a plurality of schedule candidates through random number selection using the transition probability as a weight.
[0041] The schedule evaluating section 16 has a function of selecting, for example, one schedule candidate as an optimum solution out of the plurality of schedule candidates created in the schedule planning section 15 according to the evaluation indicator (KPI) created by the machine learning section 12.
[0042] The schedule output section 17 has a function of outputting the schedule candidate evaluated by the schedule evaluating section 16 and selected as the optimum solution to the outside as a schedule candidate 17A.
(1-3) Operation Example of Production Schedule Creating Apparatus
[0043] The production schedule creating apparatus 100 has the configuration explained above. An example of a production schedule creating method executed by the production schedule creating apparatus 100 is specifically explained below.
[0044]
[0045] First, the production schedule creating apparatus 100 reads the schedule histories 11A, 11B, and 11C (step S1 in
[0046] In the schedule history storage database 11, as shown in
[0047] Subsequently, a predetermined tuning parameter is read (step S3 in
(1-3-1) Schedule Pattern Creation Processing
[0048] In the schedule pattern creation processing S20, first, as preprocessing, as shown in
[0049] In the teacher data conversion processing, first, the machine learning section 12 determines, in a round-robin manner, product pairs formed by reference products and comparative products (step S41 in
[0050] Specifically, as shown in
[0051] Subsequently, the machine learning section 12 give label values to all the product pairs as objective variables as explained below (step S43 and step S47 in
[0052] The machine learning section 12 sets the label value as the objective variable, sets a feature value based on the feature value vector as an explanatory variable, and applies the teacher data explained above to a learning algorithm such as a gradient boost tree (step S23 in
[0053] The teacher data is applied a machine learning method such as a gradient boost determination tree as explained above to thereby be modeled as a schedule pattern. The schedule pattern modeled in this way is given with a predetermined file name as shown in
(1-3-2) Evaluation Indicator Parameter Determination Processing
[0054] On the other hand, the machine learning section 12 executes evaluation indicator parameter determination processing explained below in parallel to the schedule pattern creation processing explained above (step S30 in
[0055] As an overview of the evaluation indicator parameter determination processing, as shown in
[0056] First, as shown in the middle part of
[0057] The machine learning section 12 creates a histogram to be shown in production order (equivalent to arrangement order shown in
[0058] The machine learning section 12 calculates a frequency of violation of the constraint conditions (equivalent to the violation frequency explained above) (step S33 in
[0059] Subsequently, the machine learning section 12 determines whether the number of violations calculated as explained above is 0 (step S34 in
[0060] As a result, when the number of violations is 0, the machine learning section 12 determines an evaluation indicator parameter to make a KPI value infinite when a specific constraint condition that must be always observed is violated (step S36 in
[0061] On the other hand, when the number of violations is not 0, the machine learning section 12 calculates a maximum violation amount of the pertinent constraint condition (step S35 in
[0062] Specifically, in the case of an example shown in the lower right of
[0063] As explained above, the machine learning section 12 determines, for each schedule history, evaluation indicator parameters including the maximum violation amount and the violation frequency for each of the constraint conditions # (constraint condition numbers).
[0064] The machine learning section 12 stores, as shown in
[0065] The machine learning section 12 reads, as data for which a schedule is about to be newly planned, data to be scheduled (step S6 in
[0066] Subsequently, schedule planning processing (step S9 in
[0067] The schedule planning section 15 reads a schedule pattern from the machine learning result storage DB 14, rearranges the data to be scheduled through weighted random number selection according to the schedule pattern, and creates schedule candidates as explained below (step S91 in
[0068] Specifically, the schedule planning section 15 applies the schedule pattern to the data to be scheduled and, for example, as shown in the upper right of
[0069] The schedule planning section 15 determines whether a predetermined number of schedule candidates set in advance are created (step S92 in
[0070] Subsequently, in the schedule evaluation processing (step S10 in
[0071] Specifically, as shown in step S101 in
[0072] The schedule evaluating section 16 reads, for example, evaluation indicator parameters for a constraint condition #i (i is a natural number) (step S102 in
[0073] The schedule evaluating section 16 calculates a violation point (a value 12 in the example shown in
[0074] The schedule evaluating section 16 sets, as a KPI value of the schedule candidate 2, a total of violation points of all the constraint conditions explained above (step 105 in
[0075] Subsequently, the schedule evaluating section 16 determines, as an optimum schedule candidate, a specific schedule candidate having the smallest KPI value out of all schedule candidates 1 to n using Expression (6) shown in a lower part of
[0076] The schedule evaluating section 16 repeats step S101 to step S105 until KPI values are calculated for the number of all the schedule candidates (step 106 in
[0077] The schedule evaluating section 16 selects, as an optimum schedule candidate, a specific schedule candidate having the smallest KPI value out of all the schedule candidates and instructs the schedule output section 17 to output the optimum schedule candidate (step S107 in
[0078] The schedule output section 17 outputs the optimum schedule candidate to the outside as a production schedule 17A on an output screen shown in a lower part of
(1-4) Effects and the Like of this Embodiment
[0079] According to the above explanation, with the production schedule creating apparatus 100 in the embodiment, it is possible to plan and provide a new production schedule reflecting characteristics and tendencies appearing in production schedules planned in the past.
(1-5) Application Examples
(1-5-1) First Modification
[0080] In a first modification in the first embodiment, a schedule candidate created before is taken over when a schedule candidate is created thereafter. The optimum schedule candidate selected by the schedule evaluating section 16 is re-applied to the schedule planning processing by the schedule planning section 15. A recursive calculation logic such as ant colony optimization or a genetic algorithm is applied. Consequently, it is possible to improve accuracy of the optimum schedule candidate serving as a finally calculated solution.
(1-5-2) Second Modification
[0081]
[0082] That is, the schedule evaluating section 16 corrects the transition probability to 1/KPI value=1/10.0=0.1 in an example shown in
(2) Second Embodiment
(2-1) Configuration of Production Schedule Creating Apparatus According to Second Embodiment
[0083]
[0084] The production schedule creating apparatus 100A according to the second embodiment have a configuration and operation substantially the same as the configuration and the operation of the production schedule creating apparatus 100 according to the first embodiment. Therefore, explanation is omitted concerning the same configuration and the same operation. Differences between the first and second embodiments are mainly explained below.
[0085] In the second embodiment, unlike the first embodiment, besides an information collection apparatus 102 such as an external sensor, a production line control apparatus 103 that performs exchange of data, parameters, and the like via an input interface is provided as an example of an external system.
[0086] In the second embodiment, the production schedule creating apparatus 100A captures data or parameters acquired from the information collection apparatus 102 and the production line control apparatus 103 and dynamically tunes a KPI value according to an external environment to create a production schedule.
[0087] In the production schedule creating apparatus 100A, temperature data 102A measured when the created production schedule is applied to an actual manufacturing line is stored in the schedule history storage DB 11 in advance.
[0088] In the production schedule creating apparatus 100A, when planning a production schedule, the schedule planning section 15 extracts, on the basis of the temperature data 102A automatically acquired from the information collection apparatus 102 as shown in
(2-2) Effects and the like of this embodiment
[0089] According to the above explanation, concerning a product easily affected by manufacturing conditions such as temperature, it is possible to accurately manufacture the product on the basis of an optimum production schedule.
(3) Other Embodiments
[0090] The embodiments explained above are illustrations for explaining the present invention and are not meant to limit the present invention to only these embodiments. The present invention can be carried out in various forms without deviating from the gist of the present invention. For example, in the embodiments, the processing of the various programs are sequentially explained. However, the present invention is not particularly limited to this. Therefore, the order of the processing may be changed or the processing maybe configured to operate in parallel unless contradiction occurs in a processing result.
INDUSTRIAL APPLICABILITY
[0091] The present invention can be widely applied to a production schedule creating apparatus and a production schedule creating method for creating and proposing a production schedule of products.
REFERENCE SIGNS LIST
[0092] 11 Schedule history storage DB [0093] 12 Machine learning section [0094] 14 Machine learning result storage DB [0095] 15 Schedule planning section [0096] 16 Schedule evaluating section [0097] 17 Schedule output section [0098] 100, 100A Production schedule creating apparatus