Statistical Identification of Lean Waste Factors in RCC Road Construction Using the Importance Index Method (IMPI): Evidence from Surat City, India

Abstract

Reinforced Cement Concrete (RCC) roads form the backbone of durable urban infrastructure, yet projects in this sector are routinely hampered by material wastage, equipment downtime, rework, and disrupted workflows that erode both productivity and long-term sustainability. This study identifies and ranks the principal factors driving waste in RCC road construction through the lens of Lean Construction. A structured questionnaire was distributed to 47 construction professionals – contractors, engineers, supervisors, and municipal officials – working on RCC road projects across the Surat region of India. Responses were evaluated using the Importance Index Method (IMPI), which combines a Frequency Index (FI) and a Severity Index (SI) to gauge the relative impact of each waste-causing factor. The analysis shows that poor workmanship, rework stemming from ambiguous drawings, inadequate coordination between design and site teams, and recurring design errors are the most damaging contributors to waste. Spearman’s rank correlation between the frequency- and severity-based rankings exceeded 0.97, pointing to strong internal consistency in the survey responses. The results indicate that defects, communication breakdowns, and coordination gaps are the dominant inefficiencies in RCC road construction. Building on these findings, the study discusses how combining Lean Construction practices with Building Information Modelling (BIM) can strengthen project coordination, reduce rework, and stabilise workflows, offering practical direction for more efficient and sustainable infrastructure delivery.