Balancing and Sequencing Optimization of the Mixed Model Assembly Lines

The mixed model assembly lines are a type of production line where a variety of product models similar with product characteristic are assembled. In the assembly line balancing problem, the tasks required to assemble the product model are allocated to workstations. Precedence graphs of all models should be combined to a non-cyclical joint precedence graph according to ranked positional weigh algorithm. The multiple objective sequencing problems was described and its mathematical formulation was developed considering two practically important objectives: minimizing total over and idle time, keeping a constant rate of part usage. The multi-objective genetic algorithm was applied to sequencing mixed model assembly lines. In an experiment of a mixed model assembly line balancing and sequencing problem demonstrate the feasibility of this method. The virtual simulation model and control logic of transmission was built on the base of the eM-Power software of digital factory. The workload rate and production evaluation were developed and the results were feasible.