TY - CONF TI - Enhancing sustainability in Indonesian dam construction: a lean optimization approach C1 - Singapore, Singapore C3 - Proceedings of the 34th Annual Conference of the International Group for Lean Construction (IGLC 34) SP - 473 EP - 481 PY - 2026 DO - 10.24928/2026/0182 AU - Napitupulu, Ferdinand AU - Irtanto, Edi AD - Project Manager, Infrastructure 2 & Building Division, PT. Wijaya Karya (Persero) Tbk., Jakarta, Indonesia. ferdinand.napitupulu@wikamail.id, orcid.org/0009-0007-3089-7671 AD - Project Engineering Manager, Infrastructure 2 & Building Division, PT. Wijaya Karya (Persero) Tbk., Jakarta, Indonesia. edi.irtanto@wikamail.id, orcid.org/0009-0004-1522-4717 ED - Hamzeh, Farook ED - Poshdar, Mani ED - Garcia-Lopez,, Nelly P. AB - Dams represent critical infrastructure supporting Indonesia’s food security, energy supply, flood control, and water resource management. Yet dam construction projects frequently experience time and cost overruns due to process inefficiencies, rework, and inadequate coordination among stakeholders. To enhance performance and sustainability, this study investigates the application of Lean Construction (LC) principles—particularly the Last Planner System (LPS)—as a systematic approach to waste reduction and process optimization in dam construction. Using an explanatory sequential mixed-method design (interviews, site observations, document analysis) on an ongoing dam project in Indonesia, the results show that LPS improves workflow reliability and reduces non–value-added activities, yielding measurable gains in schedule adherence, cost efficiency, productivity, and environmental sustainability through a 10–15% reduction in material waste. Key success factors include commitment-based planning, early constraint identification, and enhanced stakeholder collaboration. The study contributes a practical framework for integrating LC tools to achieve sustainable performance outcomes in complex project environments aligned with national infrastructure goals and optimize resource utilization. KW - Last Planner System KW - lean construction KW - waste reduction KW - dam construction KW - sustainable infrastructure. 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/2490/pdf L2 - http://iglc.net/Papers/Details/2490 N1 - Export Date: 19 June 2026 DB - IGLC.net DP - IGLC LA - English ER -