An Integrated Method for the Un-Paced Buffered Mixed-Model Assembly Line Balancing and Sequencing

Assembly line balancing and sequencing are two main problems in the planning of a mixed-model assembly line. In recent years, the un-paced buffered mixed-model assembly line with buffers between workstations has been widely used in industry. In order to solve the balancing and sequencing problem and ensure the efficient operation of the assembly line, an integrated method for the balancing and sequencing of unpaced buffered mixed-model assembly line is proposed. A combined precedence diagram is used to transform the mixedmodel assembly line balancing problem into a single model balancing problem. The objective of the balancing problem is to minimize cycle time under given the number of the workstations. A combined priority rule is adopted to find a solution. Based on the result of the balancing problem, the NEH (Nawaz-Enscore-Ham) algorithm is implemented for the sequencing problem to minimize the makespan considering the blocking owing to the buffers. The effectiveness of the method is verified by three cases.