An improved part grouping model for minimizing makespan in FMS

In some flexible manufacturing systems (FMSs), limited tool magazine capacity requires grouping of parts into subsets for production. Although several studies have addressed the part grouping issue research comparing the performance of models is scanty. Moreover, there is no congruency in the objectives of the present part grouping models and subsequent loading models. Traditionally, part grouping is addressed before machine loading. In this study, we overcome the drawbacks by proposing two models: model LM, which does not require part grouping, and model PGLRM (part grouping, loading and routing model), which requires part grouping. The performance of model LM serves as a benchmark. These two models also address machine loading and part routing issues concurrently. Model PGLRM's performance is then compared with the performance of model LM and few other existing part grouping models in terms of makespan and routing flexibility. Our analysis shows that model PGLRM not only results in a lower value of makespan but also imparts higher routing flexibillity as compared to existing part grouping models.