ABSTRACTThis paper addresses a class of problems, referred to as “disaggregation problems,” which lie between planning at the top level and the more detailed decisions of inventory control and scheduling at the bottom level. Most real‐world problems are sufficiently complex to warrant a sequential or top‐down approach to problem solving. However, researchers have paid scant attention to disaggregation until very recently. The resulting lack of an interfacing mechanism diminishes the utility of solution procedures for aggregate planning, inventory control, and scheduling. In order to draw attention to this gap, a taxonomy of disaggregation problems is developed for both manufacturing and service organizations. The purpose is to identify and classify problems, describe representative research, and identify unresolved