Developing an Integrated Simulation Model of Bayesian-networks to Estimate the Completion Cost of a Project under Risk: Case Study on Phase 13 of South Pars Gas Field Development Projects

The aim of this paper is to propose a new approach to assess the aggregated impact of risks on the completion cost of a construction project. Such an aggregated impact includes the main impacts of risks as well as the impacts of interactions caused by dependencies among them. In this study, Monte Carlo simulation and Bayesian Networks methods are combined to present a framework to assess the aggregated impact of risks on a construction project’s completion cost. Project risk assessment, regardless of the interactions between them, leads to prioritization of risks and does not provide any indicator to assess the aggregated effect of risks on the entire project. Achieving a nearly accurate estimate of the project completion time or cost requires consideration of the probabilities and effects of the risks, as well as the interdependencies among them simultaneously. The integrated model presented in this paper, in addition to providing a framework to evaluate the direct impact of risks on activities or work packages of a construction project, is able to assess the sensitivity of the project completion cost to the occurrence of the risks by considering the probabilities, effects and interdependencies.According to the results of the sensitivity analysis, the probabilities of “shortage of resources”, “inefficiency in project financing” and “poor design” are the main causes of delay in a gas refinery construction project.