The Last Planner System (LPS), with its now-famous PPC metric, has been used on many projects and has proven to be an effective production planning and control tool. Application of the LPS typically results in unearthing numerous problems with the production planning process and procedures that a contractor utilizes. With limited time and budgets, the construction manager needs a method to prioritize the process improvement initiatives to undertake. This paper explores the use of six-sigma based metrics and techniques to better reveal the efficacy of the production planning process as well as identify the common-cause and special-cause deviations in the production planning process. The paper will report on the adaptation of sixsigma metrics and techniques to data collected from an actual construction project. The results suggest that the developed tools will assist in focusing process improvement efforts. The sixsigma metric developed also provides a better basis for the normalization of the PPC metric such that intra-company and inter-company production processes can be compared for benchmarking and process improvement purposes.
Lean Construction, Percent Plan Complete, Control Charts, Last Planner System