Strategies to minimize construction delay: mathematical analysis

Construction project delay has become a menace contending with the construction sector opposing time, cost, and quality. It is a problem that thrives throughout the stages of the project thus debasing quality and performance. This study, which collates experts’ opinions from “Thai construction sector on the degree of influence of each key delay factors on the other, establishes the prominence (influence) level, dynamics, and impact of the controlling factors of construction delays on project schedule using a hybrid mathematical system (DEMATEL-SD modelling). Five key delay factors in this study include Design Error, Rework, Change Order, Design Change, and Productivity factors. DEMATEL analysis concludes that though all the factors are influencing but their influence levels differ. It is discovered that Rework is the most influencing factor of construction delay with a prominence value of 56.5134 and an influence degree of 20.1198%, and has mutual relationships with Design Error, Change Order, and Productivity. Design Error, which has a prominence value of 55.5492 and an influence degree of 20.1198%, is the second influencing factor, and has mutual relationships with Change Order, Rework, and Productivity. Change order is the third influencing factor with prominence value of 55.2156 and influence degree of 19.9990%. It influences Productivity, and has mutual relationships with Design Error, and Rework. Productivity is the fourth influencing factor with prominence value of 55.0712 and influence degree of 19.9467%. It has mutual relationships with Design Error and Rework. Design Change is the fifth influencing factor with a prominence value of 53.7428 and influence degree of 19.4655%. This factor is influenced by Rework and Productivity. System dynamics (SD) modeling is then employed with the DEMATEL analysis results, forming the so-called DEMATEL-SD model, to comprehensively explore the dynamics of the factors and their impact on project schedule. The simulation results reveal the importance of reducing Design Error in the pre-construction stage to minimize the magnitudes of Change Order, Design Change, and Rework during construction, which in turn, enhance the Productivity in the post-construction stage and reduce project delay in succession of time. Rework, Design Change, and Change Order must be closely monitored during the construction to ensure work productivity and on-time project completion. The results also reveal that experienced designers and uses of updated and integrated design software help reduce design errors, thus enhancing work performance in the long term. Other improvements, such as effective supervision during construction, payment system, contractor’s experience, owner’s decision system, good project management and cooperation key stakeholders, including owners, consultant, and contractors also assist in reducing the construction delay in the long term.