SMED is a method introduced by Shigeo Shingo to reduce setup durations from hours to minutes. The name implies a goal of reducing each setup to less than 10 minutes, so the number of minutes will be expressed by a single digit. SMED has been primarily developed for repetitive manufacturing, and is most beneficial when dealing with recurring setups. In this paper we present the basic theory of SMED and discuss to what extent it is applicable to custom job shops and repair job shops, such as machine shops at naval shipyards. We also present general rules how to prioritize SMED efforts, i.e., which resources should be treated first. This is important, because as we approach the goal of a single digit setup, it may be required to invest progressively more to obtain further savings.