Quantitative Risk Management Method Based on Time-Dependent Fault Tree Analysis

Abstract

This study proposed a method to visualize the risk structure using FTA (Fault Tree Analysis) as a time-dependent fault tree (TDFT) for quantitative project risk management considering the project time factor. The project risks are characterized by a risk relationship structure and an occurrence mechanism comprising the cause, risk event, and effect. The project risks are not stable; rather, their occurrence probability and importance change with the project progress. The project manager should consider risk's status and its structure for the adequate actions in a timely manner. Therefore, there is a need for a method to capture the risk structure and its changing status. Hence, this study proposes a quantitative method for structuring the project risk using TDFT. The proposed method enabled project managers to manage the project risk by visualizing the risk structure and quantitative evaluation using the TDFT, and monitoring the status using the project risk control chart. The feasibility and effectiveness of the proposed method were verified through a case study.