| The uncertainty of construction environments has made them one of the most highlighted fields in risk management. Although recently the construction industry has started to benefit from risk management and risk analysis, it has been discovered since the 1980s that construction is one of the industries most in need of applying risk management. Risk management is a procedure to control the level of risk in projects and to mitigate its consequences; therefore construction projects which deal with high level of uncertainty due to geographical factors, weather conditions, type of project, economical impact, subcontractor availability, political factors, construction delivery methods, etc. should follow an effective risk management and analysis plan. Risk analysis and assessment, one of the important steps in risk management, involves analyzing identified risk factors using a qualitative or quantitative method to determine the severity of the risk factors. This research reviews some models and methods in construction engineering literature and makes an original contribution to developing a quantitative risk analysis method based on fuzzy logic. This research seeks to develop a model based on fuzzy logic and fuzzy set theory to fill in some of the gaps between real construction environments and scientific approaches. Fuzzy logic plays a key role as the converter of natural verbal human thoughts to computational comprehensive intervals. Fuzzy logic and fuzzy set theory have been used as the foundation of this new methodology. Fuzzy intervals were used for input data in order to create more realistic assumptions than those derived from a set of crisp numbers; this leads to better results, fewer failures, and a lower tolerance for risk in construction project planning. |
