Application of lean techniques and tools in the precast concrete manufacturing process for sustainable construction: A critical review

With concrete being the primary construction material globally, optimizing its manufacturing process significantly reduces waste from demolished concrete and CO₂ emissions from cement clinker production. In this context, the integration of precast concrete manufacturing with Lean has gained increasing attraction for both on-site and off-site construction efficiency. Despite its potential, research examining this link between the lean and precast concrete manufacturing is lacking. This study presents a three-stage critical review of 35 highly relevant publications from 1999 to 2024, exploring the applications and impacts of lean techniques and tools in the precast concrete sector. The results identify that Value-Stream Mapping (VSM), and Just-In-Time (JIT) are the most prevalent lean techniques in this area. Besides, a knowledge map is developed to detail the impact of the identified 25 lean techniques and tools, offering strategic insights into future research directions. These findings can guide researchers and practitioners in selecting appropriate lean strategies for precast concrete manufacturing to reduce waste, increase value for clients, and lower emissions, towards the achievement of Sustainable Development Goals (SDGs) particularly SDG 8, SDG 9, and SDG 12.