A value stream mapping interface for manufacturing simulation

Value stream mapping (VSM) has been increasingly used to achieve lean and sustainable manufacturing. By modeling value stream maps in discrete event simulation (DES), the performance of future states of a manufacturing system can be accurately evaluated considering the dynamics and uncertainty in manufacturing processes. This paper aims at developing a formal interface between value stream maps and DES based on multiple performance metrics (e.g. production efficiency and energy consumption), which will facilitate modeling value streams in simulation. The proposed interface is developed in Unified Modeling Language (UML), where the UML class diagram is used to formalize the properties of static entity (e.g. processes), dynamic entity (e.g. products), control entity (e.g. production control), buffer entity, and measurements. The UML activity diagram is used to define production flow and information flow, and the UML state diagram is used to define the states of a dynamic entity in value stream maps and DES. A case study based on a manufacturing industry is considered, where two simulation models are developed to represent both the current and future states of the studied system. The developed simulation models are successfully validated against historical data.