A Framework for Process–Waste Mitigation in Off-site Construction during the Design Phase

Abstract

Despite accounting for a tiny percentage of total construction expenses, a wasteful design process is more likely to cause delays or errors, resulting in low productivity, budget overrun, undesirable outputs and wasting resources. This study aims to examine the design process through Lean principles to identify non-value-added activities or resources, evaluate different methods and propose solutions to eliminate or mitigate them. Value stream mapping is used in addition to statistical analysis to map the process to identify the challenges and waste areas. A framework is developed to help evaluate processes and increase efficiency during the design phases in offsite construction and built-to-order companies, thereby reducing the cost and duration of the project. Moreover, simulation is used to assess the recommended interventions. The simulation shows the estimated improvements resulting from implementing the suggested interventions, as an expected improvement of 47.3% reduction in design lead time with a utilization ratio of 13.7%. The framework is generic and applicable to all construction industry aspects. The innovation of this framework resides in the precise procedures and direction offered to improve these phases utilizing Lean tools.