Dominated by sub-contracting, mass production remains the prevalent modus operandi in the UK construction sector; this is contrary to single piece flow, a fundamental principle of lean thinking. The concept of batch sizing in a construction setting is explored together with the effects that reduced batch sizes have on construction programmes. Also examined are the practical and cultural issues that arise in reducing batch sizes both at master planning level and in the tradesman’s approach to the work. The effect of batch size reduction is quantified in two construction case studies. The observations of case study one are compared with a computer model developed by the authors, founded on the theory of lean and batch sizing. The model assesses the programmed completion time for projects using multiple trades, operating with differing batch sizes and cycle times. The theoretical background to the findings are developed as a result of the observations compared with the computer model to provide a mathematical expression to identify the relationship between batch size reduction and overall out-turn programme length. The implications for the construction sector in developing a small batch approach are discussed, and a methodology provided for calculating the effects of such an approach on overall project duration.
Batch size, lean, construction
Ward, S. A. & McElwee, W. 2007, 'Application of the Principle of Batch Size Reduction in Construction' In:, Pasquire, C.L, C. L. & Tzortzopoulos, P., 15th Annual Conference of the International Group for Lean Construction. East Lansing, Michigan, USA, 18-20 Jul 2007. pp 539-548