Product Variety in Construction: A Critical Review and Way Forward

This paper presents a critical analysis of current construction literature on product variety. In particular, two theoretical bases, namely, (i) hierarchical product breakdown and (ii) generic supply chain types, that address such conceptualization are reviewed. Three limitations were encountered, which hinder their application in measuring levels of product variety and associated disruptions in the production flow of building projects. Hierarchical product breakdowns (i) do not reflect the production sequence employed for erecting a building and (ii) do not enable spatial and layout changes (a key aspect of variety in building projects) to be appropriately framed. Supply chain types, in turn, provide only a high-level understanding of the effect of product variety (or customisation) on the production flow, and thus do not allow product variety to be assessed and compared at a project level. The paper concludes by discussing a number of conceptualizations (Work structure & Work Packages, Product Variants, Decoupling Point, Modules, and Design Structure Matrix) that can advance in the understanding of product variety in construction.