Fuzzy Contingency Determinator<sup>©</sup> a fuzzy arithmetic-based risk analysis tool for construction projects

Abstract

Construction companies always try to employ practical tools to assess risks and determine project contingency, yet the uncertain nature of risk makes it difficult to ensure that the assessment process is accurate or the agreed-upon project contingency is sufficient to deal with such uncertainty. This paper introduces a novel contingency determination procedure that employs fuzzy arithmetic in carrying out its computational steps. Fuzzy linguistic scales are used in this procedure to help experts assess the probability and impact of events using linguistic terms that are described by fuzzy numbers instead of inaccurate, single crisp values. The introduction of fuzzy logic helps experts use their own judgment—rather than relying on historical data—in determining contingency that deals with the shortcomings of applying the probabilistic risk analysis approaches in the absence of historical risk data. The paper also illustrates a new user-friendly software tool, namely, Fuzzy Contingency Determinator©, which has been developed to carry out the steps of the procedure. The main contributions of this paper are (1) the introduction of a new contingency determination procedure, based on fuzzy logic, which can handle the subjective uncertainty of experts in assessing critical events leading to risk and opportunity and in determining contingency, and (2) the implementation of the procedure using a simple and user-friendly software tool.