TY - CONF TI - Evaluating lean construction impacts on waste, lead time, rework, and cost: a case study of a commercial building project C1 - Singapore, Singapore C3 - Proceedings of the 34th Annual Conference of the International Group for Lean Construction (IGLC 34) SP - 1642 EP - 1653 PY - 2026 DO - 10.24928/2026/0219 AU - Alsharqawi, Mohammed AU - Mohammadpour, Atefeh AU - Salama, Tarek AD - AD - Associate Professor, Department of Construction Management, California State University, Sacramento, USA, a.mohammadpour@csus.edu AD - Associate Professor, Department of Construction Management, California State University, Sacramento, USA, salama@csus.edu ED - Hamzeh, Farook ED - Poshdar, Mani ED - Garcia-Lopez,, Nelly P. AB - Construction projects often suffer from workflow variability, coordination breakdowns, and material waste that drive delays, rework, and avoidable environmental impacts. This study examines how lean planning and logistics interventions affect quality and environmental performance in a large commercial office building project. A mixed-methods case study was conducted using document review, stakeholder interviews, structured site observations, and a before-and-after comparison of performance indicators. The intervention combined Value Stream Mapping to redesign sequencing, Just-in-Time material handling to reduce shortages and excess inventory, and pull planning supported by the Last Planner System®, complemented by daily stand-ups and selective preassembly. Reported outcomes indicate that material waste decreased from approximately 50 tons (projected) to 37 tons (actual), lead time and average task duration improved by about 30%, and schedule reliability increased from roughly 55% to 80% Percent Plan Complete. Rework declined from 15 to 12 incidents, labor productivity improved by about 10%, and the project finished approximately 5% under budget, consistent with an estimated 15% cost improvement. These results suggest lean production control and logistics integration can improve reliability, quality, and resource efficiency when supported by leadership, training, and clear performance measurement. KW - Lean construction KW - Last Planner System® KW - pull planning KW - Value Stream Mapping KW - Just-in-Time KW - sustainability. PB - T2 - Proceedings of the 34th Annual Conference of the International Group for Lean Construction (IGLC 34) DA - 2026/06/22 CY - Singapore, Singapore L1 - http://iglc.net/Papers/Details/2519/pdf L2 - http://iglc.net/Papers/Details/2519 N1 - Export Date: 19 June 2026 DB - IGLC.net DP - IGLC LA - English ER -