JPH11165839A - Physical distribution simulation method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a physical distribution simulation method facilitating design and production of a product data generation program and a simulation execution program even in the case of a conveying path including a branch, without a lowering of execution speed. SOLUTION: A physical distribution simulation method is provided with a step of disassembling a conveying path between article treating processes into single paths without a branch, a step of defining a start point and an end point of each single path as the generation of disappearance spots of articles, a step of inputting the kind and quantity of articles and information on a treating device used in each treating process, a step of obtaining a single path to be used from the information of the treating device used in each treating process, a step of totaling the quantity of the kind generated in each single path and computing the total quantity as the article generated quantity, a step of originating article generation data with the single path and generated time according to the article generated quantity of the single path, and a step of executing a physical distribution simulation using the article generation data.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a logistics simulation method applicable to a case where a plurality of article processing apparatuses are installed in each process and the transport route between the processes has a branch.

[0002]

2. Description of the Related Art When an article is processed, repaired, or otherwise processed in a factory or the like through several steps, it is important to control the steps including the physical distribution between the steps. Therefore, in order to efficiently arrange and operate the transport device, it is necessary to analyze and examine the distribution of articles. Therefore, a physical distribution simulation method for simulating the actual movement of an article by a computer has been developed, and several techniques have been proposed.

For example, Japanese Patent Application Laid-Open No. Hei 5-266001 discloses that a coil transfer schedule is planned for each lot.
A simulation method of logistics management in which the simulation is performed one product at a time has been proposed. In this technique, a database is created based on the amount of a lot in a work-in-process and the next process, and detailed information for each coil. In this way, a simulation is performed and the physical distribution is controlled in real time. Also, with this technology,
He claims that the feature is to automate the creation of simulation models.

Japanese Unexamined Patent Publication No. 6-203038 proposes a physical distribution / inventory behavior simulation method for a manufacturing process having a large number of steps and a wide variety of steps. In this technology, all passing processes for each material are listed on a common memory, and the operating state and the flow of the material in all the passing processes are simulated to calculate the passing time in all the passing processes. doing. This allows
This is to determine inventory fluctuations between processes and passage times for each material. Also, in this technology, by repeating the logic for sequentially selecting the best one from the stock, the passing order in all the passing processes of all the products is optimized so that the shortening of the manufacturing period and the reduction of the stock amount are optimized. Seeking.

[0005] Japanese Patent Application Laid-Open No. Hei 6-312206 discloses that for each step of a hot rolling factory, the processing is started from manufacturing conditions and the like.
A logistics simulation device for a hot rolling plant that simulates an end time has been proposed. In this technology, the processing time of each rolling mill (rough rolling mill, finishing rolling mill, coiler, etc.) is calculated in the mill pacing section, and the temperature and time of slab charging / extraction in the heating furnace combustion control section, and the heating furnace Calculate operating conditions such as temperature. Based on these, simulation is performed by an event-driven simulator, and the operation rate and the staying status of the storage space are output.

[0006]

In recent years, along with the diversification of manufactured articles, a method has been implemented in which a plurality of processing apparatuses are installed in each process, and the processing apparatuses are changed according to the types. Here, the conveyance route of the article branches between each process,
The transport route in the factory becomes complicated. As described above, when there are a plurality of processing devices in each process, in the logistics simulation,
It is necessary to handle branching transport routes.

However, the technique described in Japanese Patent Application Laid-Open No. 5-266001 basically deals with a work in progress.
Only the information on the in-process process and the next process is handled as the relationship between the object and the manufacturing process. Therefore, it cannot be basically applied to the simulation of the entire manufacturing process. Regarding the creation of the simulation model, it can be said that the automatic generation of the simulation model is poorly feasible in a large-scale and complicated model including many path branches. Actually, in the embodiment described in this publication, there is only a small model with only one work-in-process.

The technique described in Japanese Patent Application Laid-Open No. 6-203038 can handle a plurality of steps subsequent to the next step. However, although each step is omitted, it basically targets a step that does not include a branch, and rather, mainly calculates the required time of each step.

In the technology described in Japanese Patent Application Laid-Open No. 6-312206, since each process is a simulation of a hot rolling factory, each process is connected by one route. Therefore, no consideration is given to branching in product transport.

[0010] In addition, a method of imposing attribute data on product data is conceivable for determining branching of a transport route in a conventional physical distribution simulation. This is a method in which the attribute data is checked each time a conveyed product arrives at a branch point of a route, and a branch determination process is performed inside the simulator.

However, in these conventional methods, it is necessary to add complicated attribute data for determining the route to the article data. In addition, since the processing of the route determination takes time, the simulation execution speed decreases.

The present invention solves the above-mentioned problems of the prior art. Even when the transfer route between processes includes branching,
Design and production of product data generation program and simulation execution program are easy, there is no need to add complicated attribute data for path judgment to the article data, and the simulation execution speed is reduced due to the load of path judgment processing. It is an object of the present invention to provide a logistics simulation method capable of preventing the problem.

[0013]

SUMMARY OF THE INVENTION The present invention relates to a logistics simulation method in which a plurality of article processing apparatuses are installed in each step and a transport path between the steps has a branch.
(B) a step of disassembling the transport path between the processing steps for processing the articles into single paths without branching; (b) defining the starting point and the ending point of these single paths as the point of occurrence and the point of disappearance of the article. (C) the type and quantity of the article to be processed, the processing device used in each processing step, or the step of inputting article information for specifying these, and (d) the individual type used in each processing step. (E) totaling the number of articles generated in each single path by summing up the number of articles generated in each single path from the information of the processing device to be executed; Calculating as a quantity,
(F) In accordance with the number of generated items on these single paths, article generation data having a single path and an occurrence time of an article is
A logistics simulation method characterized by comprising: a step of creating; and (g) a step of performing a physical distribution simulation using the article generation data.

First, in step (a), the transport path between processes is broken down into a single route. For example, a combination of the exit side of the previous step and the entrance side of the next step is identified and set as a start point and an end point. Can be implemented. As a result, the transport path between the steps is a single path without branching. Then, step (b)
Here, the starting point and the ending point of a single path are defined as a point where an article is generated and a point where it disappears in a simulator operated by a computer. Thereby, the transport path for simulation is stored in the simulator as single-path data. The steps so far correspond to the production of the simulator.

In step (c), the kind, quantity, and processing device of the article to be processed, or article information for designating these, are input to the simulator. Here, "specify these" means that, for example, instead of inputting the processing device itself, the processing device may be specified by collectively inputting its type in device classification (standard, special specification) or the like. That's what it means. In the step (d), the single path stored in the step (b) is searched from the information of the processing device used for each type. As a result, the relationship between the type and the single path is obtained, and the relationship is stored in a file or the like as necessary.

In step (e), using the relationship between the type and the single path obtained in step (d), the number of types generated for each single path is totaled. From this, the total quantity of articles generated in each single path is obtained, and the starting point of each single path,
That is, the number of articles generated at the point where the articles are generated.

In step (f), random data for simulation is created. Basically, a single path and an occurrence time of an article are randomly generated as article occurrence data. In this case, the generation frequency is weighted according to the article generation quantity obtained in step (e). In step (g), a physical distribution simulation is performed using the article generation data.

As described above, in the present invention, all the passing steps are not enumerated. The emphasis is on simulating the flow of material items rather than simulating the operating conditions in the passage process. The simulation is performed on the flow of the material from the start point to the end point of the decomposed single path. That is, the material disappears on the entry side (end point of a single path) and exit side (start point of another single path) of each process.
Here, another single-path material is generated. As a result, the work of identifying and defining a complicated path having a branch can be greatly reduced. Further, there is no need to construct a logic for selecting an optimum one from the stock.

Also, since only the flow of material in a single path is simulated instead of the passing order in all the passing steps of all products, it is necessary to add complicated attribute data for path determination to the article data. In addition, since there is no load on the route determination processing, the calculation processing speed can be greatly improved.

[0020]

FIG. 1 is a block diagram showing an example of an embodiment of the present invention. In this example, a computer 1 that creates product data for a physical distribution simulation and a computer 2 that performs a physical distribution simulation using the computer 1 are provided. Here, the data is passed from the computer 1 to the computer 2 via the storage medium by using two computers.
A network such as an AN may be used. In addition, when there is a spare computer, the processing may be performed by one computer.

As described above, the configuration of the simulator includes two programs: a program for generating product data and a program for executing a physical distribution simulation. For these product data generation programs and simulation execution programs, the transfer route definition is shared.
This is realized by performing design / production based on the common definition contents for both the decomposition of the transport path into single paths and the definition of the start point and end point of each single path in the design / production.

FIG. 2 is a flowchart showing an article processing step in a factory where each step has a plurality of processing apparatuses. One of a plurality of processing apparatuses in each step is used for processing the article.
FIG. 2 shows an example of a factory including three steps A, B, and C for simplicity. In each step, a plurality of processing machines (processing apparatuses) are arranged such as A1, A2,..., C2. Further, in this case, between each process, the article is transported by the crane and the cart.

As described above, since each process has a plurality of processing apparatuses, the distribution route between the processes includes a branch. FIG. 3 is a diagram showing a transport route of articles in the above factory (FIG. 2). For example, an article exiting from the processing machine A1 branches to the processing machine B1 or B2.

The transport route between these steps is broken down into routes (single routes) that do not include branches. For example, the path that branches from the processing machine A1 to the processing machine B1 or B2 is A1-
It is broken down into two single paths, B1 and A1-B2. FIG.
FIG. 4 is a diagram showing, in a file format, a single route obtained by disassembling a transport route between processes in a factory. Here, a single path number (index) is assigned to each single path, and the occurrence point indicates a point where the single path starts.

Also, in this figure, the column of "single route to the vanishing point" shows the elements constituting the single route (excluding the point of occurrence). For example, the single route number 3 indicates the crane 2, the bogie 1 , Crane 3 and B1 entrance side. Here, the last element among the elements constituting the single path also serves as a point where the single path disappears. In this way, a physical distribution simulation is performed using a transport route (single route) that does not include a branch.

As for the articles, a period during which the physical distribution simulation is performed is designated, and information on the articles conveyed during the period is given. FIG. 5 is a diagram showing, in a file format, information on articles conveyed for one month (designated period) at the factory in this example. As shown in the drawing, the production amount and the processing machine used in each process correspond to the type number.

For example, the type numbers 1 to 4 correspond to the processing machine A1,
Type numbers 5 to 8 use the processing machine A2. Here, the production amount is used as the quantity of articles, but when there is no work-in-progress at the end of the month or when the work-in-progress at the end of each month can be regarded as the same, this can be substituted.

Based on the article information, the number of articles conveyed on the above-described single path (FIG. 4) is obtained. FIG. 6 is a diagram illustrating a tabulation table obtained by tabulating the number of articles for each single route occurrence point. For example, on the delivery side of the processing machine A1, product numbers 1 to
In the case of No. 4, the number of articles and the number of articles indicated in the "Breakdown by type" column are generated for the product numbers 5 to 8 on the exit side of the processing machine A2.

The transport amount of the article in each single path is
In this tabulation table (FIG. 6), the tabulation can be easily performed by further tabulating using the combination of the occurrence point and the type. For example, in the single route A1-B1, the point of occurrence is A
The total number of the product types 1 and 2 at one output side is determined by a single route A1-B.
By calculating the total number of the product types 3 and 4 at the occurrence point A1 on the outgoing side of 2, the transport amount of the article in each single path can be obtained.

Based on the information on the articles to be conveyed, the occurrence time at the point of occurrence of each single path is given to each article to create data for a physical distribution simulation.
As the time of occurrence of the article, the time range to be simulated may be appropriately divided, divided into a number of time units, and corresponding to each of them using a random number sequence according to an appropriate distribution.

FIG. 7 is a diagram showing an example of article generation data for simulation. This is obtained using a random number sequence according to a uniform distribution. As shown in the figure, a single path for transporting the article is associated with each article occurrence data. Therefore, in the physical distribution simulation, the use of the article generation data according to the present invention makes it unnecessary to determine the branch of the route between the processes.

As described above, according to the present invention, instead of minimizing the transfer time and optimizing the operation of the transfer equipment, the transfer capability under a situation where the transfer operation is completely random is verified. In such a situation, that is, in a situation in which articles are randomly generated in each single path, satisfaction of the transport capacity can be used as a reference of the minimum necessary transport capacity.

It should be noted that, in the present invention, processing steps other than the transfer equipment are intentionally excluded from the target. As a result, the work of creating the product data generation program is made more efficient, and the execution of the physical distribution simulation is made more efficient. For example, if a simulation aimed at verifying the capabilities of transport equipment such as cranes and trolleys is applied to the cold rolling mill in the steel industry, processing steps other than transport equipment (such as TCM and CAL)
Is based on the assumption that the processing capacity is sufficient. In other words, on the TCM exit side and the CAL exit side, a coil is generated at a pitch at the time of processing capacity satisfaction, regardless of the apparatus entrance side, and a physical distribution simulation in a single path is performed.

As a program for executing a physical distribution simulation, a general-purpose simulation tool can be used. In that case, it is only necessary to keep the definition of the transport route common. In this embodiment, LANNER GRO
Using UPTN's WITNESS, a part route definition function, which is a standard WITNESS function, was used as a means for defining a transfer route.

[0035]

According to the present invention, the conveyance path including the branch between the processes is decomposed into single paths not including the branches, and the generation and disappearance of the articles obtained by performing the arithmetic processing from the type information of the articles on these single paths. A logistics simulation is performed using the data. Therefore, the work of creating the product data generation program and the simulation execution program is made more efficient,
Since there is no need to add complicated attribute data for route determination to the article data and there is no load on the route determination process, it is possible to greatly improve the calculation processing speed.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an example of an embodiment of the present invention.

FIG. 2 is a flowchart illustrating an article processing step in a factory where each step has a plurality of processing apparatuses.

FIG. 3 is a diagram showing a transport route of an article.

FIG. 4 is a diagram showing, in a file format, a single path obtained by disassembling a transport path between processes.

FIG. 5 summarizes information on articles conveyed during a designated period,
FIG. 2 is a diagram shown in a file format.

FIG. 6 is a diagram showing a tabulation table obtained by tabulating the number of articles for each single route occurrence point.

FIG. 7 is a diagram showing an example of article generation data for simulation.

Continued on the front page (51) Int.Cl. ⁶ Identification code FI // G06F 17/50 G06F 15/60 612A (72) Inventor Osamu Yoshioka 1-2-1 Marunouchi, Chiyoda-ku, Tokyo Nihon Kokan Co., Ltd.

Claims (1)

[Claims] In a physical distribution simulation method in which a plurality of article processing apparatuses are installed in each step and the transport path between the steps has a branch, (a) the transport path between each processing step of processing the article is (B) a step of defining the starting point and the ending point of these single paths as a point of occurrence and a point of disappearance of the article, and (c) a type and quantity of the article to be processed. A step of inputting processing equipment used in the processing step or article information designating the same; (d) obtaining, for each type, a single path used for transporting the type from information on the processing apparatus used in each processing step; (E) calculating the total quantity of articles generated on the single path as the article generation quantity by summing up the quantities of the types generated on each single path; F) a step of creating article occurrence data having a single path and an occurrence time of an article in accordance with the number of articles generated in these single paths, and (g) performing a physical distribution simulation using the article generation data. Logistics simulation method, comprising: