Study On Flexible Job-shop Scheduling With Coupling Constraint Of Operator-Machine-Task

Operators and machines are the two most important resources in the operation process,which directly affect output and economic benefits of the workshop production system.So it is important to coordinate resources to accomplish tasks efficiently with high quality.Among them,the operator-equipment resource coordination problem in the flexible job-shop scheduling process is more prominent.On the one hand,the optimization objectives are insufficient that internal coordination degree of the “operator-equipment-task” overall system is not fully considered.On the other hand,the established model constraints are not perfect that the interaction between operators and tasks and the relationship among the factors belong operator-equipment-task system are not further clarified.In view of the shortcomings in the above flexible job-shop scheduling system,the first job was to define the coupling phenomenon and coupling coordination degree of operator-equipment-task in the job-shop,and establish the system of coupling evaluation index which considers personnel capacity and fatigue,equipment capability and task complexity with the background of E company's CNC operation workshop.Then,the centrality and cause of all the primary evaluation index to feedback their importance in the system is calculated with the method of DEMATEL,meanwhile,the results of DEMATEL are tested by ISM,and the causal relationship between primary index is showed with a picture.Based on the results of DEMATEL-ISM,the outcome factors were used as innerlatent variables,and the causal factors were used as outer latent variables to construct Structural Equation Model(SEM).Besides,the degree and direction of influence between the factors were clarified.Meanwhile,the data of outer latent variables and the influence of inner latent variables are calculated by factor load and path coefficient and used for the calculation of coupling coordination degree.In addition,the OPE content is used to define the efficiency of personnel operation,and the function of standard operation efficiency and time is drawn.Based on the influence degree of efficiency in SEM,the time function of the actual operation efficiency of the operator is corrected.Finally,the production scheduling modle with two optimization targets of the coupling coordination degree and workshop cost is established.The modle under different weights of targets is carried out with the example of six operators,eight equipments and six kinds of workpieces and actual operating efficiency function of the personnel by the method of Genetic Algorithm.The results show that the model solution can reduce workshop cost and improve personnel utilization significantly compared with the actual manual scheduling scheme;and the model solution after considering the system coupling relationship can improve workpiece qualification rate,personnel efficiency,system coordination degree and economic benefit.As a result,the model provides a certain guiding significance for actual production.