Selecting simualtion abstraction levels in simulation models of complex manufacturing systems

Abstraction level of complex simulation models such as large manufacturing systems is always a critical factor in simulation projects. It not only helps define boundaries of a simulation model but also defines the complexity and resource requirements for the model. Many a times a simple looking model grows into a complex model because of incorrect choices in abstraction level. Developing the model in stages or steps of abstraction is sometimes a favored approach. In this paper we study and analyze `why´ and `how´ these choices in abstraction level of a simulation model at various stages in a project´s life cycle results in answering the objective function more precisely. Using several automotive manufacturing case studies, We discuss the challenges relating to complexity and methodological issues, and the procedures involved in managing the same.