Research On The Optimization Method And Supporting System Of Lot Streaming Job Shop Scheduling With Variable Sublots And Intermingling Setting

The machining workshop is a typical discrete production mode with multiple varieties and small batch sizes,which is widely used in industrial fields such as aviation,aerospace,ships,construction machinery,machine tools,and automobiles.For such a workshop with multiple varieties and small batch sizes,lot streaming scheduling strategies can effectively reduce completion time,improve equipment utilization,and reduce manufacturing costs.However,traditional lot streaming scheduling mainly adopts equal or consistent sublots splitting,ignoring the characteristics of sublots intermingling.By combining variable sublots and sublots intermingling strategies,production flexibility can be further increased and production efficiency can be improved.Based on these considerations,this paper focuses on the machining workshop,studies the scheduling method based on lot streaming job shop scheduling problems,and develops a scheduling support system.The main research contents of this paper are as follows:(1)The characteristics of multi-variety and small-batch production in machine shops are addressed,and variable sublots and sublots intermingling strategies are proposed.The constraints such as lot splitting and lot processing order are considered,and a multiobjective scheduling optimization model based on lot streaming job shop scheduling is established.Additionally,a decomposition-based multi-objective Jaya optimization algorithm(MOJA/D)are proposed,and the detailed designs for encoding,decoding,Jaya updating mechanism,and local search strategies are provided.Furthermore,examples of different scales are selected to compare the performance of the proposed algorithm with other classical algorithms.(2)This study addresses the issue of random machine tool failures in the mechanical workshop and proposes a dynamic lot streaming scheduling mechanism for the variable sublots and sublots intermingling of the mechanical workshop that is aimed at random machine tool failures.The study also introduces robustness goals and delayed delivery time goals and establishes an optimization model for dynamic lot streaming scheduling of the variable sublots and sublots intermingling of the mechanical workshop.In response to the characteristics of the dynamic scheduling problem,this study uses the MOJA/D algorithm to solve the model and improves the algorithm’s decoding mechanism,population initialization method,and local search strategy.In addition,this study selects different scale examples to compare and analyze the solution performance of the proposed algorithm with other classical algorithms.(3)This study analyzes the necessity and feasibility of the lot streaming scheduling management system for a specific machining workshop from both the demand and feasibility perspectives.Detailed design is conducted on the system’s various functional modules and databases.The proposed algorithm is applied to the scheduling optimization module of the system,and the optimization results of a specific production instance are presented in detail.Through simulation of actual production situations,the effectiveness and feasibility of the developed system are verified.