Research On Modeling And Optimization Of Production Planning And Equipment Maintenance Considering Robustness

The research of lot sizing problems in manufacturing systems is mainly aimed at optimizing and determining the number of products during the planning period,with the objective to reduce the production costs of companies.In addition,equipment failures and corresponding maintenance can affect the operation of the system and have an impact on the feasibility and cost of the production plan.Due to the high correlation between lot sizing production and maintenance activities,the development of highly robust plans under fault conditions has great practical significance for enterprise to utilize resources,control costs and improve the competitive.Previous studies usually introduced failures into the model in the expected form,without fully considering the feasibility of the plan under equipment failure conditions.Aiming at the deficiencies of existing research,the robust analysis was utilized of production planning in a single device environment.Assuming that the production process is affected by equipment failures with Poisson distribution,the model that introduces robust constraints related to failures and establishes production planning decisions.The model based on the limited capacity lot sizing problem.First convert this stochastic programming problem into a deterministic model and further solve it with the optimization software Lingo.The results of the example show that compared with the planning model based on the failure expectation,the model established in this paper can guarantee the plan to achieve a higher level of robustness,and the corresponding production cost will increase to a certain extent.Further extend the system configuration to the flow line system.As the production capacity of the flow line is closely related with the configuration parameters and operation mechanism,independent research to be launched on equipment performance and lot sizing completion time from the perspective of the overall operation of the system.Firstly,the production process of the product in the flow line system was described,and then the time recursion relationship of the inprocess product start-end time intants was constructed,during which the device is affected by the failure of the exponential distribution.Finally,through the simulation calculated system lot sizing completion time.The above capability assessment method was used as the basis for constructing robust constraints to ensure the feasibility of the production plan in the implementation process.The model solving idea is the same as the single device environment.The results of the example indicated that the model could effectively ensure that the plan meets the capacity constraints with the set robustness level in the actual execution process.Through the sensitivity analysis of the robustness level,it is indicated that as the level of robustness and the number of devices increase,the corresponding production cost increases,and a relatively small amount of cost can increase the robustness of the plan to a higher level.