New Approach to Model Material-Related Problems Contributing to Project Delays Using Rotational Fuzzy Set

Abstract

Construction projects often suffer from material unavailability, which results in failure to meet set schedules. Subjective judgment is commonly used to describe the level of material availability for such projects. Construction experts often state their opinions using linguistic expressions that describe the likelihood of project delay. Fuzzy logic can be used to describe the relationship between material availability and the likelihood of project delay. This paper applies fuzzy modus ponens deduction techniques to model material availability and related project delay by incorporating Baldwin’s rotational fuzzy-set models. This deduction technique consists of three processes: the Truth Functional Modification (TFM), Inverse Truth Functional Modification (ITFM), and Lukasiewicz Implication Rule (LIR). The TFM finds the truth of a fuzzy-set, the ITFM is the inverse of TFM, and the LIR obtains the truth of an implication relation. This study presents a model that can be used to simulate material availability level and its impact on project schedule. Validation of the model showed between good and very good overall appearance and suggests that the model is applicable to the construction industry.