While risk is becoming the decision driver for a proper supply performance, and Supplier Selection (SS) is used to mitigate the Supply Risk, the few existing SS approaches for optimization under uncertainty are typically prescriptive. This shortcome has been overcome through a Risk-Efficiency-Based Supplier Selection (REBaSS) approach, which is an application of the Total Cost of Ownership (TCO) approach and gives supplier-specific guidelines for immediate and later interventions, so that an average supply cost reduction may be expected, if compared to the traditional TCO. The purpose of the research is to assess the expected positive economic impact of REBaSS on the average total cost of supply in the EPC industry, where critical supplies ...