Analysing delay factors in construction projects using Z-number approach: Insights from Pakistan

Delays are a pervasive challenge in the global construction industry, requiring more consideration to address project failure. This research proposes an improved methodology for analysing delays in the construction industry. Through a literature review, a set of 85 delay factors were identified and classified into five categories aligned with the various project phases: initiation, design, procurement, execution, and closeout. A method based on the Z-number theory was developed for the evaluation and prioritization of delay factors in the context of Pakistan. This approach incorporates expert judgment, confidence level, and experience to enhance the reliability of the evaluation. The research findings underscore the substantial influence of several critical factors on project delays. Specifically, factors such as cost inflation, contractor financial issues, inadequate project supervision and management, adverse weather conditions, insufficient skilled labour, delays in government document approvals, and unforeseen cost escalations during construction emerged as the foremost contributors to project delays.