A Simulation-Based Decision Support Tool for Circularity : Remanufacturing of an Electric Machine Case Study

Abstract: Over the last years, environmental concerns have grown regarding the pressure manufacturing activities exerts on natural resources. Many materials have been classified by the EU as scarce, rare earth elements found in magnets are amongst critical materials with high supply risk. Furthermore, this has led to increasing material costs and disruptions in the supply chain. Efforts towards increased electrification are reliant on these and other critical materials. Electric machines that power a battery electric vehicle (BEV), are vulnerable to this price variations as magnets represent high material costs. Circular business strategies present the opportunity to decouple value generation from resource use, providing a cost effective way to support net zero targets. Legislation is toughening up, increasing original equipment manufacturer (OEM) extended responsibility, which might lead to mandatory product returns that require end of life (EOL) treatment. Therefore, OEMs need a systematic way to explore EOL design strategy combinations, that can quantify the impact of a circular business model, which considers product returns and remanufacturing activities. Thus preparing to meet greener demands from customers, government and society in general. This thesis work focuses on quantifying economic and environmental factors, of circular design strategies, through simulations tools to support EOL decisions at component level. Scania’s electric machine (EM) has been used as a case study for the simulation, collecting expert input from 6 different groups. Anylogic Professional software (8.8.1 version) has been used to set up a model that represents a closed loop supply chain. An optimization experiment has been conducted, to find the cost minimum design strategies for the EM’s parts. It shows redesigning part 1 and one entire module for easy reuse minimizes overall costs. This generates economic and environmental benefits in the form of savings compared to business as usual (linear) scenario; cost savings amount to 17.7%, CO2 equivalent emissions savings to 38.7% (cradle-to-gate), and virgin material saved (from extraction) to 14.7%. The results of this work are intended to provide data supporting circular initiatives, for Scania and potentially other OEMs, for better decision making.