Combining factory simulation with value stream mapping: a critical discussion

Value Stream Mapping (VSM) is employed for the analysis of manufacturing processes. The VSM analysis leads to improve the process through the reduction of non-value added steps. The optimization is often verified by computer simulation (CS) before actual implementation in the factory. The two approaches imply a different underlying conceptual model of production: a deterministic flow of material against a stochastic queuing network. The authors discuss the critical issues, but show, with the help of an automotive case study, that they could produce positive outcomes if the goals are carefully chosen and if some rules of use are respected.