Effectiveness of lean principles in construction

This paper analyses the experiences of 16 companies who utilized lean construction principles, during the 1990 to 2003 period. A total of 41 lean principles were applied, and a total of 29 benefits were realised. Eliminating those principles that were used less than average times resulted in 11 major lean construction principles, and 6 major benefits. The two most applied lean principles included: 'Percent Plan Complete' (PPC), used on 10 projects; and 'Lookahead plan', used on 8 projects. The 6 major benefits included: (i) Cost savings, (ii) Less management cost, (iii) Project time reduction, (iv) PPC increase, (v) Less inventory, and (vi) Less rework. An analysis of the 11x6 lean principles vs. benefits table revealed that the most effective lean principle was the 'Percent Plan Complete (PPC)', seventy percent (70%) of the projects, who monitored PPC, experienced cost savings, and 60% experienced time reductions. 'All parties involved in design' principle was also very effective, reducing project times on 100% of the projects. This paper relates the major lean principles to their benefits. The experience of 16 construction companies presented in this paper will guide the future lean construction managers in selecting the most effective principles.