Non-Physical Construction Waste Quantification and Optimization Using Lean Construction Principles

Abstract

A construction project comprises of conversion and flow activities; conversion activities are value adding, and flow activities are non-value adding and generally contribute into non-physical waste (NPW). Unlike material waste, NPW impacts both time and cost. Lean construction can monitor and control this waste. Though lean practices in construction have shown remarkable improvements, NPW quantification is still not possible. To address this deficiency, current research identifies the key macro and micro level factors contributing into NPW and develops a system dynamics (SD) model using the interrelationships between these factors. The simulation results reveal that under four constant exogenous factors, 21% NPW is generated in a 24-month project. Further, the scenario based simulation highlights that lean construction can provide observable reduction in NPW. The developed model can improve the management practices by providing a comprehensive understanding of NPW, which in turn can help mitigating its impact on project progress.