Risk Assessment Of Complex Engineering Projects Considering Vulnerability

With the development of the economy and the improvement of research,many largescale complex engineering projects have emerged in China.The rapid development of practice has brought about the renewal of the theory.The traditional construction project risk management theory has been unable to adapt to the rapid changes in the internal and external environment of contemporary complex engineering projects.Understanding complex engineering from the vulnerability dimension provides a new perspective for its risk theory.Through extensive literature review,it is found that the definition of vulnerability concept has not been clearly defined in engineering for a long time.In response to this problem,Wittgenstein's Family-resemblance Philosophy and content analysis were used,a sunflower model map is used to show the connotation of the complexity of complex engineering projects.Results have shown that four core elements of project characteristics,sensitivity,adaptability and exposure can be promoted as a common vocabulary for the vulnerability of complex construction projects.20 pilot project cases were selected from the case database provided by the Mega Project Case Study and Center(MPCSC)of Tongji University.Case study was used to identify the vulnerabilities and risk factors of various types of complex engineering projects.Then,a mechanism model for the impact of vulnerability and risk in complex engineering projects was established.The basic elements and transfer rules of the fuzzy Petri nets were defined that are compatible with the characteristics of complex engineering projects.The expert knowledge processed by the cloud model was used to assign initial values to the confidence and reality in the model.The values of parameters such as certainty and ambiguity of each place node were calculated.The 4 main routes that belong to the 3 final transitions were summarized.Vulnerability-risk critical paths were identified through reverse labeling method.The complex engineering project system was divided into a system consisting of 6 risk dimensions including environment,policy,economy,technology,organization and management.Each dimension was considered as a component in a series circuit.Similarly,the whole system was equivalent to a series model.Many-to-many mapping model was used to describe the relationship between vulnerability and risk factors.The reliability function formed by the failure theory and the function limit theory transforms the qualitative expression of language into quantitative relationship.A vulnerabilityrisk reliability model was constructed.The vulnerability and risk theory of construction management were coupled in this study.The vulnerability factors were comprehensively understood in the construction process of complex engineering projects,from which the project risk analysis process was extended.Besides,it is significant for project managers to combine the characteristics of the project to improve the overall project governance decisions for risk resistance.