1. A method for identifying a critical manufacturing resource of an irreversible recovery workshop based on SIR is characterized by comprising the following steps:

step one, based on an SIR model in infectious diseases, dividing manufacturing resources of a discrete production workshop into limited manufacturing resources and non-limited manufacturing resources according to the number and timeliness which can be supplemented, wherein the limited manufacturing resources are divided into three parts: manufacturing resources that are initially susceptible to failure, also known as susceptible; manufacturing resources that are repaired after an initial failure, also known as rehabilitators; manufacturing resources that have failed initially, also known as infected; the time measurement scale is calculated according to minutes, the total quantity of manufacturing resources in the production workshop is kept unchanged and is recorded as N, and at the starting moment, the manufacturing is initially susceptible to faultsResources and failed manufacturing resources are respectively noted as: s (t)₀) And I (t)₀) The manufacturing resources repaired after the initial failure are recorded as: r (t)₀):

Representing S (t) by relational algebra₀) And I (t)₀) Comprises the following steps:

S(t₀)＝{s₁(t₀),s₂(t₀),s₃(t₀),…,s_j(t₀)}

I(t₀)＝{i₁(t₀),i₂(t₀),i₃(t₀),…,i_k(t₀)}

R(t₀)＝{r₁(t₀),r₂(t₀),r₃(t₀),…,r_m(t₀)}

wherein:

s_j(t₀) Manufacturing resources susceptible to the fault for the jth start time;

i_k(t₀) Manufacturing a resource for the kth time that a fault has occurred at the start time;

r_m(t₀) Manufacturing resources repaired after the mth initial fault at the starting moment;

unlimited manufacturing resources: new similar manufacturing resources can be supplemented at any time according to actual production needs in a production workshop;

restricted manufacturing resources: the method is characterized in that a production workshop cannot supplement new similar manufacturing resources according to actual production needs within a certain period of time;

step two, associating all manufacturing resources of the workshop with workpiece information required in a production order by utilizing production process information of the workpiece and a production plan of the manufacturing workshop in a period, determining whether the manufacturing resources have a cooperative relationship according to production process time and a production process logical relationship arranged by a generation plan, abstracting the cooperative relationship into a connecting edge in a manufacturing network, taking the weight of the edge as the processing time of the process, and finally constructing a variable-weight manufacturing network of the manufacturing workshop; manufacturing resources include machine tool equipment, tools, fixtures, gauges, and personnel;

step three, abstracting all manufacturing resources in the constructed manufacturing inter-vehicle weight production manufacturing network into a susceptible person, a rehabilitee and an infected person in an infectious disease SIR model according to the grouping result of the step one, setting the probability that the manufacturing resources susceptible to faults finally fail due to the manufacturing resources with faults, the effective action number of the manufacturing resources susceptible to faults in unit time of the manufacturing resources with faults, and the ratio of the number of the repaired manufacturing resources with faults again to the total number of the manufacturing resources with faults, wherein the ratios are respectively as follows: beta, gamma, lambda;

step four, the fault propagation rate between the adjacent manufacturing resources is the ratio of the weight of the edge between the two and the maximum weight in the whole network, beta_ijThe calculation is as follows:

wherein δ is the contact probability of two manufacturing resources, the contact probability is 1 when there is a connecting edge between the two, and the contact probability is 0 when there is no connecting edge;

step five, solving the change of the number of bottlenecks of other manufacturing resources caused by the manufacturing resources which have initially failed along with the time through an SIR model;

wherein i (t) is the number of bottlenecks of the fault-prone manufacturing resources, and the number of bottlenecks varies with time,

i₀＝I(0)/N，s₀＝S(0)/N，R₀＝λβ/γ；

step six, the importance of the manufacturing resources which have failed initially is marked by weighting the peak value of the number of the bottleneck resources and the time length reaching the peak value:

wherein ZYD (i) is the importance of the manufacturing resources for the i-th group that initially failed;

t (i) is the time when the number of manufacturing resource bottlenecks in the ith group reaches the peak value;

the number of manufacturing resource bottlenecks occurring for the ith group reaches a peak value;

K₁，K₂weights for time to peak and peak;

and step seven, reselecting different initial fault manufacturing resources and manufacturing resources susceptible to faults, repeatedly executing the steps one to six, calculating the importance of the initial fault manufacturing resources of all grouping conditions, and finally selecting key manufacturing resource nodes in the manufacturing workshop by sequencing the importance from high to low.

Background

With the increasing diversity and complexity of products, production equipment is continuously updated, and various machine tools in a traditional workshop can be replaced by a machining center; therefore, the production process becomes more complex, and each production system and production unit have extremely complex mutual exclusion and coupling relations, so that a problem worthy of research is how to enable each unit of the complex system to operate stably and efficiently.

Conventional production management focuses primarily on optimization of production schedules, and factors considered in optimization relate only to processing equipment. In a discrete manufacturing plant, however, the production process is not only determined by the availability of processing equipment, but also by special auxiliary fixtures, tools, and even gauges. To ensure the performability of a production plan, the production plan needs to be evaluated after production scheduling. The bottleneck nodes or key manufacturing resources of the manufacturing resources in the production workshop are found out in advance, and a plan is made, so that the method has important significance for improving the on-time delivery rate of the production order and maintaining the competitive advantage of enterprises.

However, in the current production practice, most enterprises rely on manual experience, and after the reduction of capacity is found in production, the possibility of bottleneck in the production system is recognized, and then bottleneck resources are searched, which may not only cause that the current order cannot be delivered on schedule, but also more possibly affect the smooth operation of the subsequent production plan of the enterprise.

At present, the research or identification method of key manufacturing resources and bottleneck manufacturing nodes in a production workshop mainly focuses on finding out the key manufacturing resources by constructing a network of the manufacturing resources and analyzing the characteristics of the network by using a complex network theory. However, this method is effective for static manufacturing networks, and cannot be used for quantitative analysis of dynamic processes that change continuously during subsequent production processes.

In addition, manufacturing resource faults in a production workshop are complex, some faults are difficult to process in a short time after occurring, and form unrecoverable faults, and the existing key manufacturing resource identification method is difficult to distinguish.

Disclosure of Invention

Aiming at the problems, the invention aims to provide an identification method of irreversible recovery workshop key manufacturing resources based on SIR, which relates manufacturing resources with workpieces required in production orders to a discrete production workshop manufacturing network according to the theory of an infectious disease SIR model, solves the time-dependent change of the number of bottlenecks of other manufacturing resources caused by the manufacturing resources which have failed initially, and marks the importance of the manufacturing resources which have failed initially through the weighting result of the peak value of the number of the bottleneck resources and the time reaching the peak value; through the ranking of the importance degrees, the key manufacturing resource nodes in the discrete workshop are finally selected, the secondary key manufacturing resources needing attention in production management in the manufacturing workshop are combed, a plan is made in advance, and the flexibility of a production organization is improved.

In order to achieve the purpose, the invention adopts the technical scheme that:

a method for identifying a critical manufacturing resource of an irreversible recovery workshop based on SIR comprises the following steps:

step one, based on an SIR model in infectious diseases, dividing manufacturing resources of a discrete production workshop into limited manufacturing resources and non-limited manufacturing resources according to the number and timeliness which can be supplemented, wherein the limited manufacturing resources are divided into three parts: manufacturing resources that are initially susceptible to failure, also known as susceptible; manufacturing resources that are repaired after an initial failure, also known as rehabilitators; manufacturing resources that have failed initially, also known as infected; the measurement scale of time is calculated in minutes, the total amount of manufacturing resources in the production plant remains unchanged, denoted N, and at the start, it is initially susceptible toThe failure affecting manufacturing resources and the manufacturing resources that have failed are respectively noted as: s (t)₀) And I (t)₀) The manufacturing resources repaired after the initial failure are recorded as: r (t)₀):

Representing S (t) by relational algebra₀) And I (t)₀) Comprises the following steps:

S(t₀)＝{s₁(t₀),s₂(t₀),s₃(t₀),…,s_j(t₀)}

I(t₀)＝{i₁(t₀),i₂(t₀),i₃(t₀),…,i_k(t₀)}

R(t₀)＝{r₁(t₀),r₂(t₀),r₃(t₀),…,r_m(t₀)}

wherein:

s_j(t₀) Manufacturing resources susceptible to the fault for the jth start time;

i_k(t₀) Manufacturing a resource for the kth time that a fault has occurred at the start time;

r_m(t₀) The manufacturing resource that was repaired after the mth initial failure at the start time.

Unlimited manufacturing resources: means that a production workshop can supplement new similar manufacturing resources at any time according to actual production needs.

Restricted manufacturing resources: means that a production workshop cannot supplement new similar manufacturing resources according to actual production needs within a certain period of time.

Step two, associating all manufacturing resources of the workshop with workpiece information required in a production order by utilizing production process information of the workpiece and a production plan of the manufacturing workshop in a period, determining whether the manufacturing resources have a cooperative relationship according to production process time and a production process logical relationship arranged by a generation plan, abstracting the cooperative relationship into a connecting edge in a manufacturing network, taking the weight of the edge as the processing time of the process, and finally constructing a variable-weight manufacturing network of the manufacturing workshop; manufacturing resources include machine tool equipment, tools, fixtures, gauges, and personnel;

step three, abstracting all manufacturing resources in the constructed manufacturing inter-vehicle weight production manufacturing network into a susceptible person, a rehabilitee and an infected person in an infectious disease SIR model according to the grouping result of the step one, setting the probability that the manufacturing resources susceptible to faults finally fail due to the manufacturing resources with faults, the effective action number of the manufacturing resources susceptible to faults in unit time of the manufacturing resources with faults, and the ratio of the number of the repaired manufacturing resources with faults again to the total number of the manufacturing resources with faults, wherein the ratios are respectively as follows: beta, gamma, lambda;

step four, the fault propagation rate between the adjacent manufacturing resources is the ratio of the weight of the edge between the two and the maximum weight in the whole network, beta_ijThe calculation is as follows:

wherein δ is the contact probability of two manufacturing resources, the contact probability is 1 when there is a connecting edge between the two, and the contact probability is 0 when there is no connecting edge;

step five, solving the change of the number of bottlenecks of other manufacturing resources caused by the manufacturing resources which have initially failed through an SIR model along with time:

wherein i (t) is the number of bottlenecks of the fault-prone manufacturing resources, and the number of bottlenecks varies with time,

i₀＝I(0)/N，s₀＝S(0)/N，R₀＝λβ/γ；

step six, the importance of the manufacturing resources which have failed initially is marked by weighting the peak value of the number of the bottleneck resources and the time length reaching the peak value:

wherein ZYD (i) is the importance of the manufacturing resources for the i-th group that initially failed;

t (i) is the time when the number of manufacturing resource bottlenecks in the ith group reaches the peak value;

the number of manufacturing resource bottlenecks occurring for the ith group reaches a peak value;

K₁，K₂weights for time to peak and peak;

and step seven, reselecting different initial fault manufacturing resources and manufacturing resources susceptible to faults, repeatedly executing the steps one to six, calculating the importance of the initial fault manufacturing resources of all grouping conditions, and finally selecting key manufacturing resource nodes in the manufacturing workshop by sequencing the importance from high to low.

The invention divides manufacturing resources of a discrete production workshop into limited manufacturing resources and non-limited manufacturing resources according to the number and timeliness which can be supplemented, and the limited manufacturing resources are divided into three parts, namely initial manufacturing resources (susceptible persons), manufacturing resources (rehabilitated persons) which are susceptible to faults after initial faults occur and manufacturing resources (infected persons) which have faults initially occur; by utilizing the production process information of the workpiece and the production plan of the workshop, all the machine tool equipment, tools, clamps, measuring tools, personnel and other manufacturing resources in the workshop are utilized, constructing a discrete production shop manufacturing network according to time and logic relations on the basis of associating the workpieces required in the production order, by setting the probability that the failed manufacturing resource will eventually fail, the number of effective actions per unit time of the failed manufacturing resource on the failure-susceptible manufacturing resource, the ratio of the number of failed manufacturing resources again to the total number of failed manufacturing resources, solving through the SIR model for the number of manufacturing resources that have initially failed causes other manufacturing resources to bottleneck over time, the importance of the manufacturing resources which have failed initially is marked through the peak value of the number of the bottleneck resources and the weighting result of the time for reaching the peak value; and then continuously adjusting the combination of the easily damaged manufacturing resources and the damaged manufacturing resources to obtain the importance of all combined manufacturing resources, and finally selecting key manufacturing resource nodes in the discrete workshop through the sequencing of the importance.

The invention has the beneficial effects that:

1) key manufacturing resources may be determined for non-recoverable faults in discrete manufacturing plants.

2) The importance of a key manufacturing resource can be quantitatively described by its propagation speed.

3) The influence of the connection relationship between the manufacturing resources on the fault propagation can be accurately described.

4) All initially failed manufacturing resources in the manufacturing plant may be traversed by enumeration.

5) By sequencing the fault propagation speeds, the secondary key manufacturing resources needing attention in production management in a manufacturing workshop can be combed, a plan is made in advance, and the flexibility of a production organization is improved.

Drawings

FIG. 1 is a classification of manufacturing resources for a manufacturing plant.

FIG. 2 is a shop manufacturing resource network building framework.

FIG. 3 is a value of the probability of contact between different manufacturing resources.

FIG. 4 is a flow diagram of key manufacturing resource node identification.

Detailed Description

The present invention will be described in detail with reference to the accompanying drawings.

A method for identifying an unrecoverable fault key node of a manufacturing network based on an SIR model comprises the following steps:

step one, dividing manufacturing resources of discrete production workshops into limited manufacturing resources and unlimited manufacturing resources according to the number and timeliness which can be supplemented, wherein the limited manufacturing resources are divided into manufacturing resources (susceptible persons) which are susceptible to initial faults and manufacturing resources (susceptible persons) which are repaired after the initial faults occurThe manufacturing resources (rehabilitative) and the manufacturing resources (infected) which have failed initially, the time measurement scale is calculated according to minutes, the total number of the manufacturing resources in the production workshop is kept unchanged and is recorded as N, and at the starting moment, the manufacturing resources which are susceptible to failure initially and the manufacturing resources which have failed are respectively recorded as: s (t)₀) And I (t)₀) The manufacturing resources repaired after the initial failure are recorded as: r (t)₀) Referring to fig. 1:

representing S (t) by relational algebra₀) And I (t)₀) Comprises the following steps:

S(t₀)＝{s₁(t₀),s₂(t₀),s₃(t₀),…,s_j(t₀)}

I(t₀)＝{i₁(t₀),i₂(t₀),i₃(t₀),…,i_k(t₀)}

R(t₀)＝{r₁(t₀),r₂(t₀),r₃(t₀),…,r_m(t₀)}

wherein:

s_j(t₀) Manufacturing resources susceptible to the fault for the jth start time;

i_k(t₀) Manufacturing a resource for the kth time that a fault has occurred at the start time;

r_m(t₀) The manufacturing resource that was repaired after the mth initial failure at the start time.

Unlimited manufacturing resources: means that a production workshop can supplement new similar manufacturing resources at any time according to actual production needs.

Restricted manufacturing resources: means that a production workshop cannot supplement new similar manufacturing resources according to actual production needs within a certain period of time.

Step two, referring to fig. 2, on the basis of associating all manufacturing resources of machine tool equipment, tools, fixtures, measuring tools, personnel and the like in a workshop with workpieces required in a production order by utilizing production process information of the workpieces and a production plan of the manufacturing workshop in a certain period, determining whether the manufacturing resources have a cooperative relationship according to production process time and a production process logical relationship arranged by a generation plan, abstracting the cooperative relationship into a connecting edge in a manufacturing network, taking the weight of the edge as processing time of the process, and finally constructing a variable-weight manufacturing network of the manufacturing workshop;

step three, abstracting all manufacturing resources in the constructed manufacturing network into a susceptible person, a rehabilitee and an infected person in an infectious disease model according to the grouping result of the step one, setting the probability that the manufacturing resources susceptible to faults finally fail due to the manufacturing resources with faults, the effective action number of the manufacturing resources susceptible to faults in unit time of the manufacturing resources with faults, and the ratio of the number of the repaired manufacturing resources with faults again to the total number of the manufacturing resources with faults, wherein the ratios are respectively as follows: beta, gamma, lambda.

Step four, referring to fig. 3, the fault propagation rate between adjacent manufacturing resources is the ratio of the weight of the edge connecting the two to the maximum weight in the whole network, β_ijThe calculation is as follows:

where δ is the contact probability of two manufacturing resources, and when there is a connecting edge between the two, the contact probability is 1, and when there is no connecting edge, the contact probability is 0.

And step five, solving the change of the number of bottlenecks of other manufacturing resources caused by the manufacturing resources which have initially failed through an SIR model along with the time.

Wherein i (t) is the number of bottlenecks of the fault-prone manufacturing resources, and the number of bottlenecks varies with time,

i₀＝I(0)/N，s₀＝S(0)/N，R₀＝λβ/γ。

and step six, marking the importance of the manufacturing resources which have failed initially by using the weighting result of the peak value of the number of the bottleneck resources and the time reaching the peak value.

Wherein ZYD (i) is the importance of the manufacturing resources for which group i initially failed,

t (i) is the time at which the number of manufacturing resource bottlenecks that occur in group i peaks.

The number of manufacturing resource bottlenecks that occur for the ith group peaks.

K₁，K₂The time to peak and the weight of the peak.

And seventhly, referring to fig. 4, reselecting different initial fault manufacturing resources, manufacturing resources repaired after the initial fault and manufacturing resources susceptible to the fault, repeatedly executing the steps from one step to six, calculating the importance of the initial fault manufacturing resources of all grouping conditions, and finally selecting key manufacturing resource nodes in the manufacturing workshop through the ordering of the importance.