Effective factors on the difference between the amount of initial estimation and the cost of construction projects (A study on Shiraz Municipality)

Actual (Final) price of construction projects are usually deviations compared to their initial estimates. At runtime, these projects face increasing in costs for various reasons and may lose their economic justification. Therefore, identifying factors affecting this price difference are one of the most important issues in this field. This study identifies the importance of the factors affecting the difference between the amount of initial estimation and the actual cost of five mega-projects of the Shiraz municipality as example. This research is descriptive-survey and data collection was done using questionnaire and interviewing tool. In order to determine the weight, priority and categories of factors, the best-worst method, gray TOPSIS and weight-quality matrix were used, respectively. The results of this study show that nine important price deviations are effective in five superstructures that fall into three broad categories: "high quality and high weight", "low quality, high weight or vice versa", "low quality and weight". According to the research findings, the "existence of adversaries" is the most influential factor in the price deviation of Shiraz municipality's superstructures.