考虑风险总关联的项目风险应对策略选择方法

本文针对考虑风险总关联的项目风险应对策略选择问题，首先结合MACBETH方法以及DEMATEL方法分析项目风险总关联；然后，在考虑项目管理者风险态度的基础上，以最大化项目管理者期望效用为目标构建考虑风险总关联的项目风险应对策略选择优化模型；最后，通过实际案例分析验证所提方法和模型的可行性与有效性，并比较分析了不同关联作用对风险应对决策的影响。结果表明：1）存在使项目管理者期望效用达到最大的最优项目风险应对预算；2）项目管理者的风险态度和对风险关联的关注程度对风险应对策略的选择和项目管理者的期望效用均有影响，在实际项目风险应对决策中均应予以考虑；3）在项目风险应对策略选择过程中，项目管理者不仅要考虑风险之间的直接关联还要重视风险之间的间接关联，而风险之间的积极关联则可以忽略。

Method of Selecting Project Risk Response Strategies Considering Total Risk Interdependence

In practice, projects are exposed to multiple risks. If the risks occur during project execution, the poor performance with increasing cost, time delays and quality flaws will appear. Thus, to ensure the success of projects, implementing appropriate project risk response strategies is especially significant. According to the literature review, in most of the existing studies focusing on selecting project risk response strategies, project risks are assumed to be independent. Only a few studies have paid attention to selecting project risk response strategies considering risk interdependences, in which only unfavorable direct risk interdependences are considered. However, in practice, there also exist indirect interdependences and favorable interdependences among project risks, which may affect the risk response decision. Thus, it is important to measure the different types of risk interdependences and then explore their effects on project risk response decision from practical and academic perspectives. In this paper, a method is proposed to measure the degrees of different types of risk interdependences and the total interdependence degree of each project risk, and an optimization model is constructed to select proper project risk response strategies considering the total risk interdependences.Firstly, the total interdependences between project risks are analyzed and measured by combining the MACBETH (Measuring Attractiveness by a Categorical-Based Evaluation Technique) method and DEMATEL (the Decision Making Trial and Evaluation Laboratory) method. Specifically, the MACBETH method is used to analyze and measure the degrees of the direct interdependences between project risks and the DEMATEL method is used to calculate the total interdependence degree of each project risk. Then, an optimization model considering the project manager's (PM's) risk attitude is constructed to select proper project risk response strategies. In the model, the objective function is to maximize the PM's expected utility, which includes utility function of the PM and weighting function of the risks. Considering that the PM's risk attitude is usually risk averse and can be expressed by concave utility function,exponential utility function is adopted in this paper. In the model, the importance of different risk is expressed by weighting function, which is composed of the total interdependence degree of the project risk and expected loss of the project risk. The constraint of the optimization model is used to meet the requirement of risk response budget. Finally, an actual case of a subway project in G city is conducted to illustrate the feasibility and validity of the proposed method. For the sake of investigating the effects of different risk interdependences and risk response budgets on risk response decision, a sensitivity analysis is carried out. In addition, pairwise comparative analyses of four situations including the direct interdependence, the unfavorable direct interdependence, the total interdependence and the unfavorable total interdependence are conducted.Some conclusions are obtained from the results of the case study, the sensitivity analysis and pairwise comparative analyses. First, there exists an optimal risk response budget in the decision process of project risk response. Second, the optimal set of project risk response strategies and the PM's expected utility is affected by PM's riskattitude and PM's attention on risk interdependence. Thus, it is necessary to consider PM's risk attitude and the risk interdependence into actual project risk response decision. Third, the PM's expected utility with the consideration of the total risk interdependence is greater than that only considering the direct risk interdependence, and the expected utility considering the unfavorable risk interdependence is larger than that considering favorable risk interdependence. Therefore, it is imperative to consider the indirect risk interdependence while the favorable risk interdependence can be neglected in the decision-making process of selecting project risk response strategies. The conclusions can provide decision support for selecting project risk response strategies in practice and our research can inspire some insights for the subsequent research focusing on project risk response considering different risk interdependences.