A Stochastic Simulation Approach for the Integration of Risk and Uncertainty into Megaproject Cost and Schedule Estimates

摘要

During the estimation phase of megaprojects, many traits must be addressed and taken into account in order to obtain realistic results. Objectives, influential factors, and their interdependencies must be accurately identified and measured. As part of this process, it is crucial to determine the uncertainty around project objectives as well as risk events that may impact the project on various levels. This paper proposes a method of defining and incorporating the uncertainty and risk events around the two main objectives of any megaproject (i.e., cost and schedule). To serve this purpose, a stochastic event simulation model which operates based on Monte Carlo simulation and uses Microsoft Project? and @Risk for Microsoft Excel? as an integrated simulation platform has been developed. The goal of the proposed model is to incorporate uncertainty and risk into the project schedule and assess the variations of the model output with respect to the deterministic estimation of cost and schedule. The focus of this study is on megaprojects that incorporate both sequential construction activities as well as cyclical manufacturing activities. The project used to validate this approach is a nuclear plant Retube and Feeder Replacement (RFR) project in Ontario, Canada.