Combining Discrete Event Simulation and Material Flow Analysis - A Modelling Tool for Eco-efficiency in Waver Production

Simulation is a common planning technique in production industry, especially in the economic evaluation of different design alternatives for production processes. This is in particular important in the field of waver production because of the huge investments in the highly sophisticated production processes. Another important issue of waver production is its impact on the environment. Along the production chain of a waver mainly different lacquers, acids, pure water and nitrogen are consumed leading to special waste handling procedures. Thus, waver production is a good example for a production process where both economic and environmental aspects have to be taken into ac-count when planning process changes. Apart from material and energy flow information relevant economic performance indicators like throughput, average waiting times or mean service times can be derived from simulation studies. This paper focuses on a novel approach integrating (economic) Discrete Event Simulation techniques with (ecological) Material Flow Analysis with a component-based software tool, the Material Flow Simulator Milan. In cooperation with a waver producer the concept of the developed modelling framework has been verified within a practical case study. The total production process has been mapped into a combined simulation model in a stepwise procedure incorporating the different production sub-systems (e.g. Lithography). In this sense using discrete simulation techniques in combination with Material Flow Analysis could be one promising holistic approach to estimate production efficiency measures with respect to their impacts on environment and costs before they come into operation.