Improving Labor Productivity Through Production Control

Min Liu1 & Glenn Ballard2

1Assistant Professor, Dept. of Civil, Construction, and Environmental Engineering., North Carolina State Univ. , 208 Mann Hall, 2501 Stinson Dr., Raleigh, NC 27695. E-mail:
2Associate Adjunct Professor at the University of California, Berkeley, and Research Director for the Lean Construction Institute. Email:


This research collected production data from a pipe installation project to study how construction labor productivity is related to four variables: Percent Plan Complete (PPC, a measure of work flow reliability), work load, work output, and workers per week. The results suggest that productivity is not improved by completing as many tasks as possible regardless of the plan, nor from increasing work load, work output or the number of work hours expended. Productivity does improve when work flow is made more predictable, thus enabling a better match of available work load with capacity (labor hours). These findings can help project managers understand the relationship between work flow and productivity and to focus on actual drivers of productivity. It may also help consulting companies pinpoint responsibility for productivity losses in claims.


construction management, labour productivity, work flow, work flow variation, Last Plannerâ„¢ System



Liu, M. & Ballard, G. 2008, 'Improving Labor Productivity Through Production Control' In:, Tzortzopoulos, P. & Kagioglou, M., 16th Annual Conference of the International Group for Lean Construction. Manchester, UK, 16-18 Jul 2008. pp 657-666

Download: BibTeX | RIS Format