Uncertainty management in time estimation of construction projects: A systematic literature review and new model development

Nowadays, the very low reliability of project planning in certainty-based approaches has led to the use of more intelligent methods for uncertainty management in construction projects. This systematic study aims to survey the methods which have been used to manage the uncertainties in time estimation of construction projects. A series of steps were undertaken during the review. The study was started with determining the purpose, selecting appropriate keywords, and reducing the selected papers using some criteria. A deeper analysis was carried out on the nal paper that met the criteria for this review. The study was limited solely to papers referred to in six top online databases. It aimed to review how the papers had been distributed by a period of publishing, country, and the domains that the methods had been applied for. The result conrmed that uncertainties which affected any project were controlled by Risk Management and Fuzzy Logic based on probability and possibility theories. Finally, a hybrid method for uncertainty management in project scheduling was proposed. The result of the implementation of this method in the construction project of Iranian Gas Company showed that the proposed method increased the accuracy of time estimation by about 8 to 24 percent.