Why is Assortment Planning so Difficult for Retailers? A Framework and Research Agenda

When retailers conduct product assortment planning (PAP), they determine (1) The variety of merchandise, (2) The depth of merchandise, and (3) Service level or the amount of inventory to allocate to each stock-keeping unit (SKU). Despite longstanding recognition of its importance, no dominant PAP solution exists, and theoretical and decision support models address only some of the factors that complicate assortment planning. This article simultaneously addresses the variety, depth, and service level aspects of PAP to provide a more thorough understanding. A review of current academic literature and best trade practices identifies open questions and directions for further research and applications.