companies often increase safety stock due to strong expected demand. however, in recent years, the automotive and electronics industries, in their efforts to stay lean and cost efficient, have experienced occasional shortages of parts due to such increased demand and disruptions in their supply chain caused by strikes and other unforeseen events (see business currents 2.2). the cost of such stockouts may include the lost revenue from the current sale, as well as a permanent loss of customers due to the ill will created.