An exploration of lean thinking for multi-storey timber housing construction: contemporary Swedish practices and future opportunities

Abstract: Construction is affected by a large amount of waste (up to 35% of production costs in Sweden) and adverse relationships which lead to low quality and profitability. In Sweden, industrialized construction is viewed as one solution to the issues of construction which has led to a number of development efforts. Based on the success of Lean Production in manufacturing and the development of Lean Construction in countries such as Denmark, England and USA, the application of Lean Construction is currently debated in Sweden. However, Lean Construction theory seems unable to explain the development of industrialization in Swedish construction. Consequently, there is need of further research on how to better match industrialized construction with Lean Construction theory. The aim of this research is twofold; 1) explore how Lean Construction theory can be used to gain a deeper understanding of Swedish multi-storey timber housing construction and 2) explore how an understanding of contemporary practices can help extendthe theory of Lean Construction to better facilitate research on industrialized construction. Currently, there is a Swedish governmental investment campaign supporting development of timber housing construction. Consequently, this is a good opportunity to explore the applicability of Lean Construction. Based on an understanding of the Lean philosophy, contemporary Swedish timber construction practices are analysed through three case studies; element prefabrication, volume prefabrication, and an initiative combining volumes and elements. The driving force in the development of applications for Lean Construction is production system design for increased control over construction events - stability (reliability) and better control (predictability) are sought through the reduction of variety in working practices, supply chains, etc. Consequently, improving work flow is the primary target of Lean Construction. An analysis of the contemporary timber element prefabrication reveals three main issues; 1) complicated design decisions, 2) poor design documentation, and 3) deficient production planning which, from a Lean Construction perspective, obstruct work flow. However, the root cause of work flow issues is identified as a lack of value management which causes ripples all through the production system resulting in variety and poor control. Results from volume and volume/element prefabrication indicate that value management greatly improves production system design. These well-defined technical platforms, so called ‘product offers', represent a new way of thinking in the delivery of value for multi-storey housing construction. The Lean characteristics of the ‘product offer' are product specifications based on customer value, value stream management through specific resources and activities, management of value-adding activities for flow, flexibility to customer demands enabling pull, and transparency for continuous improvements (perfection). Based on these characteristics, the ‘product offer' is viewed as one possible change-agent in the adoption of Lean Construction for Swedish multi-storey housing construction.