Mixed Model Assembly Line Balancing Design And Sequencing Optimization For Compressor

The implementation of mixed model assembly line allows different products to be assembled on the same line which can avoid redundant investment. Assembly line balancing and sequencing optimization which are critical in assembly line design and management is an efficient way to optimize resources in enterprise. This paper studied the mixed model assembly line balancing problem (MMALBP) and sequencing optimization based on the original data from a compressor manufacturer in Dalian.Firstly, according to the current situation analyzed the causes of the low productivity and the necessity of the utilization of assembly line. After analyzing the assembly process similarity of the three kinds of compressors, the feasibility of implementing mixed model assembly line was guaranteed. Standard working time was reformulated which reflected the real working situation with sampling method and X-σ control chart. This working time data served as basic information for the mixed model assembly line balancing problem and sequencing optimization.Then, mixed model assembly line balancing problem was transformed into simple model by calculation of the mixed average working time. According to the production demand the cycle time (CT) was determined which decided the pace of the line. The mathematical model was established choosing the smoothness index (S1) as the objective function.Thirdly, the model was solved with branching and bounding method and a feasible solution was gotten. The optimal solution was gained by LINGO11.0. According to the optimal solution9workstations were needed which met the constraint of human resources. Improving by31.25%the monthly production capacity was840units as the demand required. The rate of balancing was86.5%and the smoothness index was1.6which indicated the balance status had reached a considerable excellent level.Finally, as for the sequencing problem a model whose objective function was to minimize the production cycle was established. After comparing the solution got by traditional reciprocal method and the solution got by LINGO, the better solution was adopted. The finish time for one circulation was161.25min under the optimal solution. The work load and work time utilization were calculated under the optimal sequence.