A heuristic operation sequence-pattern identification method and its applications in the design of a cellular flexible assembly system

Following the success of flexible manufacturing systems (FMSs), their counterpart, flexible assembly systems (FASs), have been developed to automate factories further. As in a FMS, the cellular approach is considered as the most feasible and flexible configuration for a FAS by researchers. Because of the differences between manufacturing and assembly operations, the logic of cell formation between a FMS a FAS is not the same. This paper discusses the similarities and differences between FMSs and FASs, and assembly cell design problems. Since the time for assembly operation is usually relatively short, the transfer time is thus very crucial for the performance of assembly systems. Therefore a good assembly cell should be constructed in a way that the flows of products within this cell are mostly in sequence. More in-sequence flows usually have the advantages of smaller flow distance, easier material-handling problems and more efficient production. In order to achieve these advantages, we propose a heuristic sequence-pattern identification method that can identify sequence patterns among the routeings of different products. The identified patterns can then be used for designing assembly cells with more in-sequence flows. An experimental study is shown to illustrate the applications of sequence patterns in the designing process of an assembly cell.