Product and Process Complexity in Construction: An Exploratory Study Using Bill-of-Materials (Bom)

Abstract

Modularity has been applied in the automotive and computer industries to simplify production and supply chain management. Instead of coping with dozens of hundreds of parts, these are grouped into modules produced and delivered by suppliers, simplifying products assembly. Bill-of-Materials (BOM) is a technique used in manufacturing to map the modules that form a product at distinct hierarchical levels. Yet, to the best of our knowledge, such technique has not been widely explored in construction to assess the complexity involved in buildings production. This paper uses BOM in an empirical case (a house of approximately 400 square meters built in Southeast region of Brazil) to analyse (i) the total number of different modules forming a building and (ii) how these modules are distributed throughout the work packages for producing such building. The results show that the studied house is formed by (at least) 522 different modules, which are unevenly distributed across 18 work packages. Some work packages (e.g. concrete pillars and walls) have more than 200 modules whereas others (e.g. foundations) have less than 10. This suggests the potential for repackaging and organizing the delivery of modules as kits to ease production tasks.