Guidelines for resolving safety constraints using the Last Planner System in Zimbabwean construction projects

Abstract

Construction projects in Zimbabwe continue to experience performance challenges arising from persistent safety constraints. This study examines how the Last Planner System (LPS), a key Lean Construction tool, can be applied to reduce these safety-related barriers. The aim is to provide construction stakeholders with practical, evidence-based guidelines for implementing LPS to improve safety performance on project sites. A quantitative survey was conducted among contractors registered with the Construction Industry Federation of Zimbabwe (CIFOZ), yielding 130 valid responses. Data analysis employed descriptive statistics, mean score analysis, exploratory factor analysis (EFA), and partial least squares structural equation modelling (PLS-SEM). Results show that LPS significantly alleviates two major categories of safety constraints, namely technical and managerial inadequacies, and employee-related and project delivery concerns, supported by p-values below 0.05 and path coefficients of 0.409 and 0.520, respectively. From these findings, practical LPS implementation guidelines are proposed. It emphasises multilevel planning (master, phase, look-ahead, and weekly), systematic identification and mitigation of safety risks, enhanced worker participation to strengthen ownership of safety practices, and improved workflow reliability to prevent last-minute changes that commonly lead to accidents. Although the study is limited to Zimbabwean projects and relies primarily on quantitative data, it demonstrates that LPS offers a viable and impactful strategy for improving construction site safety. Broader adoption of LPS can support performance enhancement across the sector and aligns with Sustainable Development Goals 9 and 11.