An integrated technique for the internal logistics analysis and management in discrete manufacturing systems

A novel hierarchical and iterative technique is presented for the analysis and management of the internal logistics of manufacturing systems. The method effectively integrates the value stream mapping (VSM) tool, the analytic hierarchy process (AHP) approach, and discrete event simulation. Starting from a concise description of the manufacturing system obtained by the VSM graphical approach, so as to identify nonvalue-adding activities, a detailed and standardised description is obtained by the unified modelling language (UML). Then the AHP technique is used to rank the system anomalies, singling out the major ones. Further application of the VSM tool produces an overall picture of the desired manufacturing system internal flow, and the UML description details the to-be system activities. Finally, the use of discrete event simulation allows the quantitative verification of the effects of the changes in the production system. The proposed technique is a tool to systematically improve the internal logistics of complex production systems while assessing the system dynamics and corresponding performance improvements. An application of the method to a real case study enlightens its effectiveness.