Integration Of Production Planning And Scheduling Based On RTN Representation Under Uncertainties

Production planning and scheduling is an important basis for production decisions.Making reasonable and effective production planning and scheduling can greatly improve the production efficiency of enterprises.There are many uncertain factors involved in the process of making production plan and scheduling,such as production cost,product demand,delivery time,utility and so on.The uncertainties mentioned above have a decisive influence on the formulation of production planning and scheduling.With the rapid development of economic globalization,the competition among enterprises becomes increasingly fierce.Considering the uncertainty in the process of making production planning and scheduling can arrange production more reasonably and improve the competitiveness of enterprises.This paper mainly studies the integration of production planning and scheduling based on RTN representation in an uncertain environment.The general research contents and innovation points are as follows:(1)The uncertainty of product demand was considered in the production planning layer,and the discrete time modeling method was used to establish the uncertain planning model of mixed integer linear programming.The material balance constraint,demand constraint,production capacity and productivity fluctuation constraint,inventory capacity and inventory quantitative constraint,and pollutant emission quantitative constraint were considered.The product demand uncertainty is treated by the knowledge of the opportunity constrained programming theory,and the opportunity constrained uncertainty model is transformed into a certainty model with specified confidence level.(2)In the production scheduling optimization problems based on RTN representation and modeling method based on the continuous time of a specific unit events point to establish continuous time mixed integer linear uncertain model,add the uncertainty of the utility as a constraint to the model,which consider resource balancing,capacity constraints,demand constraints,time constraints,order constraints,utility supply and utilities use time constraints.The fuzzy theory is used to deal with the uncertainty of public works,and the uncertain model of public works is transformed into a deterministic model with membership degree.(3)A two-layer integrated model of multi-cycle production planning and scheduling is established,that is,through the correlation between product production in each production period,the two are integrated and optimized.Finally,the iterative solution of the planning layer and the scheduling layer is realized by using the rolling horizon optimization strategy.