JP3226582B2 - System simulation equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a simulation apparatus for a system which simulates 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. Things.

[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 from experience and past data, and it is determined by simulation whether or not the specifications required by the system are satisfied. ing. In a conventional simulator, a time when a failure occurs as a repair when a trouble occurs is set as a maintenance work start time, and a time when the repair time is simply added to the time when the failure occurs is set as a maintenance work completion time, and the simulation is performed as a maintenance work completion time.

[0003]

However, in an actual site, it is rare that a maintenance staff is assigned to each work, and in most cases, one maintenance staff is provided for a plurality of or all facilities. The fact is that maintenance work is being performed. With conventional simulators, simulations are performed far away from the actual operating state of the system.For this reason, the simulation results are expressed as a higher operation rate, which generates errors, which are considered when considering capital investment. Had been a problem.

[0004]

According to the present invention, the work or time of maintenance personnel is taken into account in a simulation.
By proceeding with the simulation, the system can be simulated in a more realistic manner. That is, the present invention relates to a system simulation apparatus that simulates an operation state of each of the facilities, assuming that a failure has occurred in the facilities, for a system including a plurality of facilities. Creating means for creating a work schedule indicating a time zone of a normal operation in the facility, and a time zone of a maintenance work for repairing the failure for the facility in which the failure is assumed, and the work schedule. Reorganizing means for reorganizing, when the time slots of the maintenance work overlap among a plurality of the facilities, the reorganization means removes the maintenance work in order to eliminate the duplication. The maintenance work of the facility whose start time is earlier is prioritized, and the time period of the maintenance work of the facility which is later is shifted later.

According to another aspect of the present invention, there is provided a system simulation apparatus for simulating an operation state of work in equipment constituting a system, wherein a normal work and an abnormal work are displayed on a screen by a node, and the normal work is performed. The sequence relationship between the arcs with the first attribute
The first attribute is displayed on the screen, and a sequence relation between a node representing abnormal work and a node representing the normal work or another node representing abnormal work is represented by an arc having a second attribute. Distinguished from arcs with
The two sequence relationships can be identified on the screen by displaying the two sequence relationships on the screen . Further, another invention is, in the simulation of the system that simulates the operation status of the work in equipment constituting the system, the screen on the node working
The displays and the sequence relationship between these tasks in a first
Is displayed on the screen by an arc having the attribute of, and the sequence relation between the operations in the abnormal state is distinguished from the arc having the first attribute by the arc having the second attribute.
The sequence relationship between operations in the event of an abnormality can be identified on the screen by displaying the sequence on the screen .

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments 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. : The repair sequence at the time of failure can be easily set and programmed. Hereinafter, this function is referred to as a “restoration sequence setting” function. : When it is assumed that a failure has occurred during the execution of a plurality of operations that operate in parallel, it is possible to automatically simulate the operation schedule in consideration of the repair operation of the maintenance staff. Hereinafter, this function is referred to as a “restoration 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 which allows an operator to select the above two functions in this system. 2
Denotes an input unit for inputting data such as a keyboard and a mouse operated by an operator. The mode selected by the operator using icons, keyboard commands, etc.
Realizes the above two functions in the simulator body 3. When the operator selects the "repair sequence setting" mode, the simulator 3 executes the "repair sequence setting" function. When the operator selects the “restoration sequence simulation” mode, the “restoration sequence simulation” function is executed. In FIG. 1, reference numeral 4 denotes 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 denotes a database, which includes work data 7, failure data 5, and restoration data 6.

<Repair Sequence Setting Mode> A repair sequence setting function in this mode is newly provided with the following background. That is, in the conventional simulator, as a repair method in the case of occurrence of a failure, a simulation is performed assuming that a repair time for the equipment and work is given stochastically and the process proceeds 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, it is difficult with a conventional simulator to skip the subsequent steps when a serious failure occurs or to skip to another repair sequence and execute it. When the work order is described in a dedicated simulation language, specialized knowledge is required for setting and changing the work order, and it is difficult to intuitively understand the work order. The "repair sequence setting" function is characterized in that the operator can grasp the work sequence and set the skip sequence while providing intuitive understanding. Hereinafter, the “restoration sequence setting” mode will be described in detail.

In the "repair sequence setting" mode, one work is represented by a node having a predetermined symbol, and a transition relation (sequence) from one work to the next work is represented by an arc having an arrow symbol. Things. In the example of FIG. 2, the simulator recognizes that the operation of the node 2 is performed after the operation represented by the node 1. As shown in FIG. 3, the work database 7 has an identifier (ID) for each “work”.
Each “work” includes “work name”, “work content”, “machine used”, “normal succeeding work”, and “abnormal succeeding work”. The "work name" is displayed on the CRT 4 so that the operator can recognize 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 used to perform the work. In the example of FIG. 3, the operation “c” with the operation identifier “3” indicates that “c part is attached and caulked”, which is performed using “robot C”.
“Normal successor work” stores a work succeeding the work in a normal state. “Abnormal succeeding work” stores a work following the work when an abnormality occurs. How the fields of the "normal successor work" and the "abnormal successor work" are filled will become clear later.

As shown in FIG. 3, the failure database 5 is provided with data for each "operation", and includes an "average failure interval" (MTBF), an average repair time m required for repair, and a repair time m. And 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, reference numeral 8 denotes an area for displaying an "operation" menu when the operator intends to set a repair sequence. In this area,
As an example, five menus of “work definition”, “work deletion”, “normal preceding relationship”, “abnormal preceding relationship”, and “relation deletion” are prepared.

When the "work definition" menu is selected, a desired work can be set and displayed in the display area 10 as a node. What work can be defined is
It is displayed on the screen areas 11 and 12. The work menu displayed in the areas 11 and 12 is generated from the work database 7. The scroll bar 13 enables a large number of operations to be displayed and selected even when only a menu limited to the area 12 can be displayed. For example, to define the work a and display it in the area 10, the following is performed.
First, the operation “a” is displayed in the areas 11 and 12 using the scroll bar 13, and the operation “a” is displayed in the area 11 of the mouse.
Click. Then, the mouse cursor 9 is moved to the position 13 where the operation "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 the operations b and c as shown in FIG. 4, the operation b is selected on the menu 11, the mouse cursor is moved to the display position 14, and the mouse is clicked. Further, the user selects work c on the menu 11, moves the mouse cursor 9 to the display position 15, and clicks the mouse. In the example of FIG. 5, a, b, c, d,
Six operations e and z are defined.

To define the precedence of these operations,
After clicking "normal predecessor relation" in the operation menu 8 and selecting the operation, the preceding work is clicked first, and the subsequent work is clicked later. In the example of FIG.
If the user clicks on the operation “1” first and then clicks the operation “2” later, an arrow is drawn from “1” to “2”, the preceding relationship of those operations is indicated to the operator, and the operation database is displayed. “2” is written in the “subsequent work” field of the work “1” of No. 7 (see FIG. 3). Further, in the example of FIG. 5, when the work sequence is defined in the order of a, b, c, d, e, and z, these a, b, c, d, e,
Let the node of z be a → b → b → c → c → d → d → e → e →
Click with the mouse in the order of z.

Next, how to deal with a failure when it occurs will be described. In the example of FIG.
Is to assemble and crimp c parts, and if a failure occurs in operation c, leaving it unattended results in a product failure. Therefore, the countermeasure operation should be shifted to the operation “z” in which the steps after the operation “c” are skipped and discharged.

Therefore, first, "preceding relation at abnormal time" is selected as an operation. 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.
Thereby, the connection relationship between the nodes “c” and “z” is displayed. In the work database, work “z” is stored as “following work in case of abnormality” of “c”. In order to display the antecedent relationship at the time of abnormalities separately from the antecedent relationship at the time of normality,
The arrow 20 may be displayed in red, for example.

Further, the following countermeasures may be performed. That is, when a failure occurs, a specialized work for dealing with the failure is defined, and when a trouble occurs, the work is skipped. For example, when a failure occurs in the operation “d”, the operation “f” is required, and after the operation “f”, the operation returns to the operation “e” which is a succeeding operation of the operation “d”. . In order to do this, first, the operation "f" is defined in the "operation definition" menu, and then, the "preceding relationship at abnormal time" operation is selected. Then, the nodes "d", "f", "f", and "e" are clicked with the mouse. Then, a precedence relationship as shown in FIG. 6 is obtained between the operations “d”, “f”, and “e”. In the work database, the work “f” is stored as “following work at abnormal time” of “d”, and the work “e” is stored as “following work at abnormal time” of “f”.

Thus, the normal operation and the abnormal operation can be easily set. The operation “delete operation” in the operation menu deletes the registered operation from the display screen, and the operation “delete relation” deletes the preceding relation. 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. It is also easy to intuitively understand the set work order.

<Repair Sequence Simulation> The above-described repair sequence setting mode is mainly for setting and relating operations related to each other to the sequence. In the “repair sequence simulation” mode, when a failure occurs in any of a plurality of operations (at least one operation) operating in parallel and a maintenance person is involved in the operation process, the operation in which the failure has occurred is performed. And simulate how the rest of the work is affected. If it is possible to assign one maintenance person to all work steps, no matter which work fails, the maintenance work will not affect other work. However, in order for a limited number of maintenance staff to repair all the work, 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 management differs depending on which work maintenance is given priority and which work maintenance is delayed. That is, the “repair sequence simulation” of the present embodiment is performed to simulate how the repair of the failed work affects the remaining work.
The mode is significant.

FIG. 7 shows the configuration of the fault database used in this mode. For the sake of simplicity, it is assumed that work is performed at a certain factory using _three machines M ₁ , M ₂ and M ₃ . According to FIG. 7, the machine M ₁ work P
_1i (work time PT 21 seconds) and work P _{1i + 1} (work time 29
Performs a second), the machine M ₂ work P _2j (working time 18
Seconds) and work P _{2j + 1} (work time 15 seconds).
_{In step 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 operation P _2j using the machine M _2
Is started at time 45 seconds (ST ₂ ), the operation P _3k using the machine M ₃ is started at time 46 seconds (ST ₃ ), and the operation P _1i using the machine M ₁ is started at time 49 seconds (ST 2 ₁ ) What you do. Since the operation P _2j has an operation time of 18 seconds, the operation P _3k has an operation time of 14 seconds, and the operation P _1i has an operation time of 21 seconds, a Gantt chart in the case where these operations operate normally is shown in FIG. Become like Here, ET ₁ ~ET ₃ is the end time of each task.

Here, as shown in FIG. 9, the machines M ₂ , M
_It is assumed that a failure has occurred at times TH ₂ and TH ₂ with respect to ₃ , respectively. From FIG. 8, since the repair times for the work P _2j and the work P _3k are 6 seconds and 16 seconds, respectively, 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,
The Gantt charts and FIGS. 9 and 10 show how to simulate the effect on other work processes when only one maintenance person is used, that is, simulate the order in which work is reorganized. This will be described with reference to the eleventh control procedure.

In this embodiment, reorganization is performed according to the following rules. That is: maintenance personnel are to be dispatched preferentially to a failure that has occurred earlier. The flowchart in FIG. 11 is a control procedure for the simulator 3 to reorganize the work schedule assuming that a failure has occurred. What kind of failure is assumed is input from the failure data database 5.

First, in step S 1, a simulation completion time and failure / repair data are input from the keyboard or the failure database 5 from the input unit 2. Respectively TH ₂ failure in the work P _3k and work P _2j, TH ₃ (T
H ₂ is slower than TH ₃ ). In step S2, the simulation t is determined to be "0".

In step S3, when it is assumed that a maintenance person can be assigned to all of the failed work out of all the works operating in parallel, the time of the work to be completed ET _i (“completed”) Time). Completion time ET _i
Is ET _i = ST _i + PT _i . Then, at M ₂ and M ₃ , the completion time ET _i
Since the failures are assumed to have occurred by now, when the time for repairing those failures is 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 operations P _1i , P _2j and P _3k are 70 and 6 respectively.
This is 9,76 seconds.

Next, in step S4, the earliest time T _min in ET _i and the corresponding work S are obtained. In the example of FIG. 9, the time 69 of the operations P _2j of M ₂ is T _min. In steps S5 to S12, a determination is made as to whether or not the repair work is to be performed on the work S found in step S4. That is, in step S5, it is determined whether or not the operation S includes a repair operation. In the example of FIG.
Since operation S (operation P _2j ) includes a repair operation, step S
The determination at 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 in comparison with the failure occurrence time of another work for which the repair work has not been determined.

In the example of FIG._Two Failure occurrence time TH_Two 
Is 61 according to FIG._Three Failure occurrence time TH_Three Is 5
6 and the judgment in step S6 is_Two j about
It becomes NO. Then, in step S11, the restoration work is not yet completed.
Search for the machine with the fastest failure among the confirmed machines
The repair work is performed on the machine and the failure occurrence time T
H_i (Repair work is finalized).
This is M in the example of FIG._Two If a failure occurs,
Personnel is M_Three Maintenance work, M_Two Maintenance work
I can't do it. Therefore, M_Two Maintenance work is M
_Three After the maintenance work of the
You. Then, in step S12, in step S4
The repair start time of the searched work S is shifted behind. Or
Comb M_ThreeAs shown in Fig. 10
Determine. That is, the machine M_Three Repair work is TH_Three At
It is said to be started, and the machine M_Two Repair work is postponed
It is. In this case, the machine M_Two For the shortest, machine M_Three 
End time of the repair work (ie, TH_Three + RT_Three ) Until
Can be expected. And the machine M_Two End time ET for
_Two Is ET_Two = TH_Two + @RT_Three − (TH_Two -TH_Three )｝ + RT_Two + PT_Two − (TH_Two ー ST_Two )｝ = RT_Three + TH_Three + RT_Two + PT_Two -TH_Two + ST_Two  Becomes Then, returning to step S3, the
Completion time ET_i Ask for. At the moment, M_Three P
_Three k Is determined, undetermined is M₁ P_1 i And M_TwoP_Two j
 And M_Three P_{Three k + 1} It is. Therefore, in step S4,
Among the unconfirmed works, the work that finishes the earliest work is
Machine M₁ Work P_1 i Is determined. This P_1 i Is repair
Since no work is included, NO is determined in step S5,
Thereby, in step S8 and step S9, the work S
Machine M₁ Working on P_1 i Is determined. at the time
The new unconfirmed work is M₁ P_{1i + 1}And M_Two P_2jWhen
M_ThreeP_{3k + 1}It is.

Returning to step S3 again, the process proceeds to step S4, where the new earliest end operation S is M ₂
Is determined. Then, YES is determined in step S5, it is determined as YES also step S6, step S8, in step S9, repair schedules for tasks P _{2 j} of the machine M ₂ is determined. Thus, FIG.
According to the simulator 3 shown in the first control procedure, it is possible to execute a simulation in consideration of maintenance work. Such a simulation facilitates proper allocation of personnel and cost calculation in advance. In addition, the system can be simulated more realistically.

<Modifications> The present invention can be variously modified without departing from the spirit thereof. For example, in the “restoration sequence setting” mode, the preceding relationship is indicated by an arrow, but the symbol is not limited to the arrow, and any symbol can be used as long as the directional relationship is understood. In addition, the distinction between the abnormal state and the normal state can be made by the line thickness in addition to the color.

In the "repair sequence simulation" mode, the number of maintenance personnel is one, but the present invention can be applied to a case of a plurality of personnel. In such a case, the simulation can be performed by delaying the maintenance work time when the number of maintenance personnel is insufficient, and executing the simulation in the other state as it is in other cases. In addition, the maintenance personnel are dispatched preferentially to the failure that has occurred first. However, a weight may be added to the work restoration, and the maintenance may be performed in the order of the weight. The present invention may be applied to a system including a plurality of devices or to an apparatus including a single device. Needless to say, the present invention can be applied to a case where the present invention is achieved by supplying a program to a system or an apparatus.

[0029]

As described above, the present invention relates to a system comprising a plurality of facilities, which simulates the operating state of each facility, assuming that a failure occurs in the facility. In the simulation device, for each of the facilities, a work schedule indicating a time zone of a normal operation in the facility, and a time zone of a maintenance operation for repairing the failure for the equipment in which a failure is assumed is further performed. Creating means for creating, and reorganizing means for reorganizing the work schedule, the reorganizing means, when a plurality of the facilities, when the time period of the maintenance work overlaps, the reorganization means, In order to eliminate the maintenance work, the maintenance work of the equipment having the earlier start time of the maintenance work is prioritized, and the maintenance work of the later equipment is later performed. And wherein the shifting. That is,
Considering the maintenance staff time in the simulation time,
The simulation can now proceed, and the system can be simulated more realistically.

According to another aspect of the present invention, there is provided a simulation apparatus for a system for simulating an operation state of work in equipment constituting a system, wherein a normal work and an abnormal work are displayed on a screen by a node. The sequence relationship between the arcs with the first attribute
The first attribute is displayed on the screen, and a sequence relation between a node representing abnormal work and a node representing the normal work or another node representing abnormal work is represented by an arc having a second attribute. Distinguished from arcs with
The two sequence relationships can be identified on the screen by displaying the two sequence relationships on the screen .

According to another aspect of the present invention, there is provided a system simulation apparatus for simulating an operation state of a work in a facility constituting a system, wherein the work is displayed on a screen by a node, and a sequence relation between the works is described in a first step. Displayed on the screen by an arc with attribute 1
Then , the sequence relation between the operations at the time of the abnormality is determined by the arc having the first attribute by the arc having the second attribute.
By displaying on the screen differently from the above , the sequence relation between the operations at the time of abnormality can be identified on the screen . For this reason, it is possible to intuitively grasp the work sequence in the normal state and in the abnormal state.

[Brief description of the drawings]

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

FIG. 2 shows “repair sequence setting” in the system of FIG.
FIG. 7 is a diagram showing a typical display example in a mode.

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

FIG. 4

FIG. 5

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

FIG. 7 is a view showing data contents of a database used in a “repair sequence simulation” mode.

FIG. 8

FIG. 9

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

FIG. 11 is a flowchart showing a control procedure in a “repair sequence simulation” mode.

[Explanation of symbols]

 1 Mode setting section, 2 Input section, 3 System simulator body, 4 Display section, 5 Failure database, 6 Repair database, 7 Work database.

Claims (6)

(57) [Claims] 1. A system comprising a plurality of facilities,
In a system simulation device that simulates the operation state of each of the facilities, assuming that a failure has occurred in the facilities, for each of the facilities, a time period of normal work in the facility, and a failure. For the equipment assumed, further comprising: a creation means for creating a work schedule indicating a maintenance work time zone for repairing the failure, and a reorganization means for reorganizing the work schedule, The knitting means, when a plurality of the facilities have overlapping time periods of the maintenance work, in order to eliminate the duplication, perform the maintenance work of the facility whose start time of the maintenance work is earlier. A system simulation apparatus, wherein priority is given to shifting the time period of the maintenance work of the later equipment to a later time. 2. The reorganization means reorganizes the work schedule only when the number of the facilities whose time periods of the maintenance work overlap is larger than an assumed number of maintenance personnel. The system simulation device according to claim 1, wherein 3. The system according to claim 1, wherein the reorganizing unit reorganizes the work schedule in order from the facility having the earliest scheduled completion time of all the work including the normal work and the maintenance work. A simulation device for a system according to claim 1. 4. A system simulation apparatus for simulating an operation state of work in equipment constituting a system, wherein a normal work and an abnormal work are displayed on a screen by a node.
And, and the sequence relationship between normal operating arc by displaying on said screen having a first attribute, other nodes that represent the nodes representing abnormal operations, the or abnormal working with node representing the normal working Yes said first attribute by arc having a second attribute sequence relationship between
A simulation apparatus for a system, characterized in that the two sequence relationships can be identified on the screen by displaying the two sequence relations on the screen in distinction from the arcs . 5. The system simulation apparatus according to claim 4, wherein the abnormal operation is a recovery operation from a failure. 6. A simulation device for a system for simulating an operation state of a work in a facility constituting a system, wherein the work is displayed on a screen by a node,
The sequence relation between these operations is displayed on the screen by an arc having a first attribute, and the sequence relation between the operations in an abnormal state is distinguished from the arc having the first attribute by an arc having a second attribute. Separately the screen
A simulation apparatus for a system, wherein a sequence relation between operations at the time of an abnormality is made identifiable on the screen by being displayed above .