Research On Sequencing Problem For Mixed Flow Workshop For Engine Assembly

With the promotion of the JIT production model in the actual workshop,the production system propose higher requirements for the planning schedule.The engine production workshop has the characteristics of mixed flow production,long process,long processing routes and complicated production rules.Production plans based on experience and manual preparation has limited effect on actual production,thus there's an urgent demand for more scientific and accurate mixed flow production plan to adopt to achieve full production capacity of the workshop.This paper studies the scheduling of assembly workshops in the context of FAW Xichai Engine Production Enterprises.A two-stage sequencing model based on the upstream and downstream division of the line body is proposed through analyzing the actual production situation of the workshop.In this model,sequence optimization of the assembly line in the upstream is first preformed,followed by sequence optimization of the testing and oil-sealing line in the downstream.In this way,a sequencing plan for the entire assembly shop is obtained.For the sequencing problem of mixed flow assembly line in the firat stage,a mixed-flow sequencing model with minimum production batch aiming at product production equalization,station load balancing and minimum completion time is constructed and an Modified artificial bee colony algorithm is designed to solve the problem.Through the simulation experiment,the Modified Artificial Bee Colony algorithm is compared with the standard Artificial Bee Colony algorithm.Taking the production order of the actual workshop as an example,the Modified Artificial Bee Colony Algorithm is used to get the optimal production sequence of the production order on the assembly line,which provides a scientific basis for actual production scheduling.As for the "assembly-test-oil seal" multi-line sequencing problem in the second stage,the logistics simulation platform Plant Simulation is used to establish the assembly simulation model of the assembly workshop.A test line sequence optimization model based on mapping relationship is constructed for the optimization of the test line sequence.The GA module built in the simulation platform is used to optimize the solution.For the oil-seal line sequence optimization problem,the heuristic algorithm based on actual production rules is used for sequencing.Under the optimal flow sequence of the upstream mixed flow production sequence,the optimal test line production sequence and oil-seal line production sequence with the least buffer accumulation and the shortest completion time are obtained by solving the same instance problem.Resquence the problem after adding random factors into the simulation model to verify the real-time sequencing method for the model's multi-line sequencing problem.The research results in this paper can enrich the research on the sequencing problem of mixed-flow assembly workshop.The proposed two-stage sequencing method for mixed-flow assembly workshop not only provides a method to solve similar problems,but also provides decision-making basis for the actual workshop,which has practical value.