1. 1Motivation Increasingglobalcompetitionandcostpressureforceenterprisesandsupplychains to discover undetected cost-saving potentials. In particular, interfaces to the p- curement market are a promising ?eld for improvement. Recent developments in international trade outline the high in?uence of uncertain deliveries and highly volatile prices on the companies' costs. A vital question in research, industry, and politics addresses theoptimal procurement policy of rawmaterialsdue touncertain future prices and is of highest priority for the ?rms' success and even the wealth of a nation....