چكيده به لاتين
An efficient construction industry is a necessary precondition for the development of the construction process. In this regard, in this dissertation, the aim is to identify the most common, critical and most important reasons for the delay and its negative effects on road construction projects. Because, the main goal of the project manager is to complete the project on time in the projected budget, while meeting the specified quality requirements and other specifications. To this end, a framework for identifying, prioritizing delays, and critical activities is presented in this dissertation. Using the introduction in a real case study related to the country's freeway projects, it has been implemented. Its devices were first considered using existing scientific sources, studies that exist in free development projects, and then exposed to the judgment of experts using the Delphi technique, up to 14 were identified in the first stage of the Delphi technique. . Then, a schedule for free road projects consisting of 13 activities was designed. In the continuation of this research, a questionnaire was prepared to collect information and 48 answers were carefully completed by experts. The validity and reliability of this questionnaire were evaluated using the Cochrane relationship. The validity and reliability of this questionnaire were evaluated using the Cochrane relationship. Then, by performing the second Delphi stage, 5 important and critical delays were selected from the identified delays, and the statistical delay functions of each of them were calculated. Then, by designing 19 scenarios, the extent of the impact of each of the critical effects on the activities was reported. . Also, for further analysis, the scenario study is designed to be the most important factor of positive impact on critical activities and on two activities (basis and excavation) and different probabilities have been calculated using the widely used technique of increasing activity time. The reported value of the scenarios is prioritized at each stage. The conclusion obtained from the simulation of 19 scenarios, scenario 18 (the most critical impact of each activity) had the greatest impact on the project time. The most important factor for all critical activities of the second scenario (the impact of credit and interpretive problems during excavation activities) had the greatest impact on increasing project time. The results of simulation of 5 scenarios related to the most important factors affecting the most critical critical activities (excavation) The first scenario (the effect of problems related to evaluation during excavation activities) had the greatest impact on increasing project time.
