JPH05204888A - Simulation device for system - Google Patents

Abstract

PURPOSE:To perform simulation in a form nearer to the actuality by defining normal work and fault correction work at retrieved facility and performing the simulation. CONSTITUTION:A mode setting part 1 recognizes a mode selected by an operator by using the icon and a keyboard instruction, etc., of an input part 2, and two functions are realized at a simulator main body 3. In such a case, a data base includes working data 7, fault data 5, and correction data 6. Normal working data and fault correction working data are set on the facility targeted to apply the simulation, and scheduled completion time for all work in which maintenance work is included in the normal work is found, and the facility in which the fault occurs in the earliest time is retrieved. Furthermore, the simulation is performed at the facility in which the normal work and the fault correction work are defined, and the normal work and the fault correction work are retrieved by the simulator main body 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a system simulation device for simulating the operating state of a system, for example, by giving failure data such as a failure probability and a repair time to equipment constituting a system such as a production line. It is a thing.

[0002]

2. Description of the Related Art Conventionally, when designing a system such as a production line, the reliability of each facility and each work is set based on experience and past data, and it is judged by simulation whether the specifications required by the system are satisfied. ing. In a conventional simulator, the time at which a failure occurs is used as the maintenance work start time, and the time when the repair time is simply added to the failure occurrence time is used as the repair work completion time to carry out the simulation.

[0003]

However, there are few cases where maintenance personnel are assigned to each work at the actual work site, and in most cases, one maintenance staff has a plurality of maintenance staffs or equipments for all work. The reality is that maintenance work is being performed. In the conventional simulator, the simulation is performed in a form that is far from the actual operating state of the system.Therefore, the simulation result shows a higher operating rate and causes an error, and this error occurs when considering capital investment. Was a problem.

[0004]

According to the invention, the work or time of maintenance personnel is taken into account in the simulation,
By advancing the simulation, the system can be simulated in a more realistic manner. That is, the present invention provides each of the work in the equipment constituting the system with failure data, and in the system simulation apparatus for simulating the operating state of the system including maintenance when a failure occurs, the equipment to be simulated is A means for setting normal work data and failure repair work data, a means for obtaining a scheduled completion time of all work including maintenance work in normal work in each facility,
A means to search for equipment that is said to have caused the failure the earliest,
It is characterized by further comprising means for deciding normal work and failure repair work in the searched equipment, and simulating these normal work and failure repair work in the searched equipment.

Another structure of the present invention is to represent normal work and abnormal work by nodes in a system simulation apparatus for simulating the operating state of work in equipment constituting the system, and between normal work. Is represented by an arc having a first attribute, and the second attribute represents a sequence relationship between a node representing abnormal work and a node representing the normal work or another node representing abnormal work. It is characterized by being represented by an arc having.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment to which the present invention is applied will be described below with reference to the accompanying drawings. The simulator system of this embodiment mainly has the following two functions. : A repair sequence at the time of failure can be easily set and programmed. Hereinafter, this function is referred to as a "repair sequence setting" function. : When it is assumed that a failure occurs during execution of a plurality of works operating in parallel, it is possible to automatically perform a work schedule simulation in consideration of repair work by maintenance personnel. Hereinafter, this function is referred to as a "repair sequence simulation" function.

<System Configuration> FIG. 1 is a block diagram showing the overall configuration of this simulator system. In FIG. 1, reference numeral 1 denotes a mode setting unit that allows an operator to select the above two functions in this system. Two
Is an input unit for inputting data such as a keyboard and a mouse operated by an operator. The mode selected by the operator using the icon or keyboard command is the mode setting section 1
Recognizes and realizes the above two functions in the simulator body 3. When the operator selects the "restoration sequence setting" mode, the simulator 3 executes the "restoration sequence setting" function. When the operator selects the "repair sequence simulation" mode, the "repair sequence simulation" function is executed. In FIG. 1, reference numeral 4 is a data display unit such as a CRT. In the "restoration sequence setting" mode, a screen as shown in FIG. 4 is displayed. Reference numeral 5 is a database, and this database includes work data 7, failure data 5, and repair data 6.

<Repair Sequence Setting Mode> The repair sequence setting function in this mode is newly provided with the following background. That is, in the conventional simulator, as a repair method when a failure occurs, the simulation is performed by probabilistically giving the repair time of the equipment and work and proceeding to the next step after the repair time has elapsed. Also, the work order is described in a dedicated programming language,
The simulation was executed according to the description.
Here, when a serious failure occurs, it is difficult for the conventional simulator to skip the subsequent steps or skip the repair sequence and execute the repair sequence. When the work sequence is described in a dedicated simulation language, specialized knowledge is required to set or change the work sequence, and it is difficult to intuitively understand the work sequence. This "restoration sequence setting" function is characterized in that it enables the operator to intuitively understand the work sequence and the setting of the skip sequence. The detailed description of the "restoration sequence setting" mode will be given below.

In this "restoration sequence setting" mode, one work is represented by a node having a predetermined symbol, and a transition relationship (sequence) from one work to the next is represented by an arc having an arrow symbol. It is a thing. In the example of FIG. 2, the simulator recognizes that the work of node 2 is performed after the work represented by node 1. As shown in FIG. 3, the work database 7 is provided with an identifier (ID) for each "work".
Each "work" consists of a "work name", a "work content", a "machine used", a "normal successor work", and an "abnormal successor work". The “work name” is displayed on the CRT 4 so that the operator recognizes the work name. The “work content” is displayed on the CRT 4 so that the operator can recognize the content of the work. "Used machine"
Indicates what kind of machine is specifically used to perform the work. In the example of FIG. 3, the work “c” having the work identifier “1” is “assemble and tighten the parts c”,
It is performed using "Robot C". The “normal successor work” stores the work that follows the normal work. The "abnormal subsequent work" stores the work that follows the work when an abnormality occurs. How to fill in the fields of "normal successor work" and "abnormal successor work" will become clear from the description below.

Further, as shown in FIG. 3, the failure database 5 is provided with data for each "work". The "mean failure interval" (MTBF), the average repair time m required for the repair, and the repair m It consists of the standard deviation σ of time m. FIG. 4 is an example of a display screen on the CRT 4 in the "restoration sequence setting" mode. In the figure, 8 is an area for displaying a menu of "operation" when an operator is going to set a repair sequence. In this area,
As an example, five menus of "work definition", "work deletion", "normal preceding relationship", "abnormal relationship", and "relationship deletion" are prepared.

When the "work definition" menu is selected, a desired work can be set and displayed as a node in the display area 10. What kind of work can be defined is
It is displayed in the screen areas 11 and 12. The work menus displayed in the areas 11 and 12 are generated from the work database 7. The scroll bar 13 makes it possible to display and select many works even when only the menu limited to the area 12 can be displayed. For example, in order to define the work a and display it in the area 10, the following is done.
First, the work "a" is displayed in the areas 11 and 12 by using the scroll bar 13, and the work "a" is displayed in the area 11 of the mouse.
Click. Then, the cursor 9 of the mouse is moved to the position 13 where the work "a" is to be displayed, and the mouse is clicked. Then, the work a is displayed on the screen 10 of the CRT 4 as shown in FIG. If it is desired to further define works b and c as shown in FIG. 4, select work b on the menu 11, move the mouse cursor to the display position 14, and click the mouse. Further, the work c is selected on the menu 11, the mouse cursor 9 is moved to the display position 15, and the mouse is clicked. In the example of FIG. 5, a, b, c, d,
Six tasks e and z are defined.

To define the precedence relationship of these tasks,
After clicking the "predecessor relation at normal time" in the operation menu 8 to select the operation, the preceding work is clicked first, and the subsequent work is clicked later. In the example of FIG.
If the work of "1" is clicked first and the work of "2" is clicked later, the arrow is drawn from "1" to "2", the precedence relation of those works is shown to the operator, and the work database “2” is written in the “subsequent work” field of the work of “1” of 7 (see FIG. 3). Further, in the example of FIG. 5, when defining a work sequence in the order of a, b, c, d, e, z, these a, b, c, d, e,
The node of z is a → b → b → c → c → d → d → e → e →
Click with the mouse in the z order.

Next, how to define the coping work when a failure occurs will be described. In the example of FIG. 3, work “c”
Is to assemble and crimp parts c, so if a failure occurs in work c, leaving it unattended will result in a product failure. Therefore, the coping work should be shifted to the work "z" in which the steps after the work "c" are skipped and the work is discharged.

Therefore, as the operation, first, the "abnormality preceding relationship" is selected. Next, in order to define the preceding work as “c” and the succeeding work as “z”, the node “c” → “z” displayed by the mouse is clicked. Then, the simulator 3 sets and displays an arrow 20 between the nodes "c" and "z" on the display screen, as shown in FIG.
As a result, the connection relation between the nodes "c" and "z" is displayed. The work “z” is stored in the work database as the “successive subsequent work” of “c”. In addition, in order to display the antecedent relationship at the time of abnormality separately from the antecedent relationship at the normal time,
The arrow 20 may be displayed in red, for example.

Further, the following coping work may occur. That is, when a failure occurs, a specialized work for dealing with the failure is defined, and when an abnormality occurs, this work is skipped. For example, if a failure occurs in the work “d”, the work “f” is required, and after the work “f”, the work “d” is returned to the work “e” that is a succeeding work of the work “d”. .. To do this, first define the work "f" in the "Work Definition" menu and then select the "abnormality precedence relationship" operation. Then, with the mouse, the node “d” → “f” → “f” → “e” is clicked. Then, the preceding relationship as shown in FIG. 6 is obtained between the works “d”, “f”, and “e”. Then, in the work database, the work “f” is stored as “d's subsequent work at abnormal time” and the work “e” is stored as “successive work at abnormal time” of “f”.

Thus, the normal work and the abnormal work can be easily set. The "work deletion" operation in the operation menu deletes the registered work from the display screen, and the "relationship deletion" work deletes the preceding relationship. Thus, according to this mode function, a desired sequence can be easily skipped and set, and the operator does not need to have a dedicated simulation language. In addition, it is easy to intuitively understand the set work order.

<Repair Sequence Simulation> The above-mentioned repair sequence setting mode is mainly for setting and relating works related to each other in a sequence. In this "repair sequence simulation" mode, a failure occurs in any of a plurality of works (at least one work) that operate in parallel, and when the maintenance staff is involved in the work process, the work in which the failure occurred It simulates how the rest of the work, including, is affected. If one maintenance person can be assigned to all work processes, no matter which work fails, the maintenance work does not affect other work. However, in order to repair all work with a limited number of maintenance personnel, if a failure occurs in a plurality of work processes at the same time, it is necessary to delay the repair of any work. The cost of production control varies depending on which work is given priority to maintenance and which work is delayed. That is, the “repair sequence simulation” of the present embodiment is applied to a simulation of how the repair of the faulty work affects the rest of the work.
Mode has significance.

The structure of the fault database used in this mode is shown in FIG. In order to simplify the explanation, it is assumed that a factory uses _three machines M ₁ , M ₂ , and M ₃ for work. According to FIG. 7, in the machine M ₁ , the work P
_1i (work time PT21 seconds) and work P _{1i + 1} (work time 29
Performs a second), the machine M ₂ work P _2j (working time 18
Second) and work P _{2j + 1} (working time 15 seconds), and machine M
_{At 3} , work P _3k (work time 14 seconds) and work P _{3k + 1} (work time 16 seconds) are performed.

In the example of FIG. 8, the work P _2j using the machine M ₂ is performed.
At time 45 seconds (ST ₂ ), work P _3k using machine M ₃ starts at time 46 seconds (ST ₃ ), work P _1i using machine M ₁ starts at time 49 seconds (ST ₁ ) to do. Since the work P _2j has a work time of 18 seconds, the work P _3k has a work time of 14 seconds, and the work P _1i has a work time of 21 seconds, the Gantt chart when these works normally is shown in FIG. Like Here, ET _{1 to} ET ₃ are end times of the respective works.

Here, as shown in FIG. 9, the machines M ₂ , M
_It is assumed that a failure occurs in time points TH ₂ and TH _{2 for 3} , respectively. From FIG. 8, the repair times for the work P _2j and the work P _3k are 6 seconds and 16 seconds, respectively. Therefore, when there are two maintenance personnel, the end times ET ₂ and ET ₃ are extended to 6 seconds and 16 seconds, respectively. The result is as shown in FIG. here,
Gantt charts and diagrams of FIGS. 9 and 10 are used to simulate the effect on other work processes when there is only one maintenance staff, that is, to simulate the order in which work is reorganized. The control procedure of 11 will be described.

In this embodiment, reorganization is performed according to the following rules. That is: ： Maintenance personnel will be dispatched preferentially to the failure that occurred earlier. The flow chart of FIG. 11 is a control procedure for the simulator 3 to reorganize the work schedule assuming a failure. The failure data database 5 is used to input what kind of failure is assumed.

First, in step S1, the simulation completion time and the failure and repair data are input from the keyboard or the failure database 5 from the input unit 2. The obstacles are TH ₂ and TH ₃ (T ₃ ) in work P _2j and work P _3k , respectively.
H ₂ occurs later than TH ₃ . In step S2, the simulation t is set to "0".

In step S3, among all the works that operate in parallel, when it is assumed that maintenance personnel are assigned to all the works in which a failure has occurred, the work is completed at the time ET _i ("Complete Called "time"). If there is no failure, no maintenance is required, so the completion time ET _i
Is ET _i = ST _i + PT _i . Then, at M ₂ and M ₃ , the completion time ET _i
Since it has been assumed that failures have occurred up to this point, when the repair times of these failures are considered in RT _i (i = 2, 3), the completion time is ET _i = ST _i + PT _i + RT _i . Therefore, the Gantt chart is as shown in FIG. 9, and the completion times of the respective works P _1i , P _2j and P _3k are 70 and 6 respectively.
It will be 9,76 seconds.

Next, in step S4, the earliest time T _min in ET _i and the work S corresponding thereto are obtained. In the example of FIG. 9, the time 69 of the work P _2j of M ₂ is T _min . In steps S5 to S12, with respect to the work S found in step S4, a definite work as to whether or not to perform the repair work is performed. That is, in step S5, it is checked whether or not the work S includes a repair work. In the example of FIG. 9,
Since work S (work P _2j ) includes repair work, step S
The determination of 5 is YES, and the process proceeds to step S6. In step S6, it is checked whether or not the failure occurrence time of this work S is the earliest as compared with the failure occurrence time of other work for which the repair work is not fixed.

In the example of FIG. 9, M₂ Failure occurrence time TH₂ 
9 is 61 from FIG. 9, and M₃ Failure occurrence time TH₃ Is 5
6, and the determination in step S6 is work P._2 j about
It becomes NO. Then, in step S11, the repair work is not performed.
Search for the machine with the earliest failure occurrence among the confirmed machines
Then, repair work is performed on the machine at the failure occurrence time T
H_i Shall be started in (confirmation of repair work).
In the example of FIG. 9, this is M₂ In case of failure of the
The personnel is M₃ Maintenance work of₂ Maintenance work
I can't do it. Therefore, M₂ Maintenance work is M
₃ After the maintenance work of
It Then, in step S12, in step S4
The restoration start time of the searched work S is shifted behind. Or
Comb, M₃As for the maintenance work about
Determine. That is, machine M₃ Repair work is TH₃ At
It is supposed to be started, and the machine M₂ Repair work postponed
Be done. In this case, the machine M₂ For the shortest, Machine M₃ 
End time of repair work (ie, TH₃ + RT₃ )
Can be expected. And the machine M₂ End time for ET
₂ ET₂ = TH₂ + {RT₃ -(TH₂ -TH₃ )} + RT₂ + {PT₂ -(TH₂ -ST₂ )} = RT₃ + TH₃ + RT₂ + PT₂ -TH₂ + ST₂  Becomes Next, returning to step S3,
Completion time ET_i Ask for. At the moment, M₃ Of P
_3 k Is confirmed, and M is undetermined₁ Of P_1 i And M₂Of P_2 j
 And M₃ Of P_{3 k + 1} Is. Therefore, in step S4,
Of the unconfirmed work, the work that ends the earliest work is
Machine M₁ Work P_1 i Is judged. This P_1 i Is repair
No work is included, so it is determined to be NO in step S5,
As a result, in step S8 and step S9, the work S
Machine M₁ Work P_1 i Will be confirmed. at the time
New unconfirmed work is M₁ Of P_{1i + 1}And M₂ Of P_2jWhen
M₃Of P_{3k + 1}Is.

Returning to step S3 again, the process proceeds to step S4, where the new earliest work S is M ₂
Is judged. Then, YES is determined in step S5, YES is also determined in step S6, and in steps S8 and S9, the repair schedule for the work P _{2 j} of the machine M ₂ is fixed. Thus, Figure 1
According to the simulator 3 shown in the control procedure of No. 1, it becomes possible to execute the simulation considering the maintenance work. Such simulation facilitates proper staffing and cost calculation in advance. Also, the system can now be simulated in a more realistic manner.

<Modifications> The present invention can be modified in various ways without departing from the spirit thereof. For example, in the "restoration sequence setting" mode, the preceding relationship is indicated by the arrow, but the squeezing is not limited to the arrow, and any directional relationship can be understood. Further, it is possible to distinguish between abnormal time and normal time not only by the color but also by the thickness of the line.

Further, in the "restoration sequence simulation" mode, the number of maintenance personnel is one, but the present invention can be applied to the case of a plurality of personnel. In such a case, the simulation can be performed by shifting the maintenance work time later when there is not enough maintenance personnel, and in other cases by executing the maintenance work as it is. Further, although the maintenance personnel are dispatched preferentially to a failure that occurs first, weight may be added to the work repair and maintenance may be performed in the order of weight. The present invention may be applied to a system including a plurality of devices or an apparatus including a single device. Further, it goes without saying that the present invention can be applied to the case where it is achieved by supplying a program to a system or an apparatus.

[0029]

As described above, the present invention provides a system for simulating the operating state of the system including the maintenance data in case of failure, by giving the failure data to each work in the equipment constituting the system. In the simulation device, a means for setting normal work data and failure repair work data in the equipment to be simulated, a means for obtaining a scheduled completion time of all the work including maintenance work in the normal work in each equipment, and the failure as soon as possible. And a means for deciding the normal work and the failure repair work in the searched equipment, and simulating the normal work and the failure repair work in the searched equipment. It is characterized by doing. That is, it becomes possible to proceed with the simulation by considering the time of the maintenance staff in the simulation time, and to simulate the system in a more realistic manner.

According to another aspect of the present invention, in a simulation device of a system for simulating the operating state of work in equipment constituting the system, normal work and abnormal work are represented by nodes, and a sequence between normal work is provided. The relationship is represented by an arc having the first attribute,
It is characterized in that a sequence relationship between the node representing the abnormal work and the node representing the normal work or another node representing the abnormal work is represented by an arc having the second attribute.

According to still another configuration of the present invention, in a system simulation apparatus for simulating an operating state of a work in equipment constituting the system, the work is represented by a node, and a sequence relation between these works is defined as a first relation. It is characterized in that it is represented by an arc having an attribute, and the sequence relationship between works at the time of abnormality is represented by an arc having a second attribute. Therefore, it is possible to intuitively grasp the work sequence in the normal time and the abnormal time.

[Brief description of drawings]

FIG. 1 is a block diagram of a simulation system to which the present invention is applied.

[FIG. 2] “Repair sequence setting” in FIG. 1 system
The figure which shows the typical example of a display in mode.

FIG. 3 is a diagram showing the contents of data in a database used in the “restoration sequence setting” mode.

[Figure 4]

[Figure 5]

FIG. 6 is a diagram showing how the display screen changes as the operation progresses in the “restoration sequence setting” mode.

FIG. 7 is a diagram showing the contents of data in a database used in a “restoration sequence simulation” mode.

[Figure 8]

[Figure 9]

FIG. 10 is a diagram showing how the display screen changes as the operation progresses in the “restoration sequence simulation” mode.

FIG. 11 is a flow chart showing a control procedure of “restoration sequence simulation” mode.

[Explanation of symbols]

 1 mode setting part, 2 input part, 3 system simulator main body, 4 display part, 5 failure database, 6 repair database, 7 working database.

Claims (5)

[Claims] 1. A simulation device of a system for simulating an operating state of the system including maintenance work when a failure occurs by giving failure data to each operation in the equipment constituting the system, Means for setting normal work data and failure repair work data, means for obtaining the scheduled completion time of all work including normal work and maintenance work in each equipment, and means for searching for equipment that is determined to have the earliest failure And a means for deciding normal work and failure repair work in the searched equipment, and simulating these normal work and failure repair work in the searched equipment. 2. The simulation apparatus of the system according to claim 1, further comprising means for determining a scheduled completion time of all work including normal work in each facility and maintenance work, wherein the searching means is a scheduled completion time. About the earliest equipment,
The equipment includes means for determining whether or not the equipment includes a failure repair work, the simulation means determines the normal work and the failure repair work for the equipment including the failure repair work and having the earliest failure occurrence time, and these It is characterized in that normal work and failure repair work are simulated in the searched equipment. 3. A system simulation apparatus for simulating an operating state of work in equipment constituting a system, wherein normal work and abnormal work are represented by nodes, and a sequence relationship between the normal work is defined by a first attribute. Is represented by an arc having a second attribute, and the sequence relationship between the node representing the abnormal work and the node representing the normal work or another node representing the abnormal work is represented by the arc having the second attribute. Characteristic system simulation device. 4. The simulation device of the system according to claim 3, wherein the abnormal work is recovery work from a failure. 5. A simulation device of a system for simulating an operating state of a work in equipment constituting a system, wherein the work is represented by a node, and the sequence relation between these works is represented by an arc having a first attribute. ,
A system simulation device characterized by expressing a sequence relationship between works in an abnormal state by an arc having a second attribute.