Fuzzy logic model for initial project screening with consideration of decision position

In planning for a construction project, the owner often has several alternatives regarding the site or the building that are available for selection. Evaluation of the project alternatives and then ranking them in preference so as to select the overall best one for implementation is the key issue that influences project success. This paper proposes a model for initial screening of project alternatives with consideration of the owner’s decision position that is reflected by the priority differences between the decision factors. The model uses the fuzzy inference system to perform mapping from the estimates of the factors or the inputs for an alternative to its score or the output. In order to illustrate the model, hypothetical alternative sites of a housing project for a developer firm are assumed and an example fuzzy inference system is built to simulate evaluation and ranking of them. First, three variables, i.e. project size, project conditions, and unit development cost, are used as the input variables that determine the desirability of a site in initial project screening. Next, the linguistics values of the input and output variables each are defined with a set of membership functions. Then, the fuzzy rules that represent the owner’s decision position in a possible scenario are set up. For given inputs, the output is produced by mathematical operations on the rules. The assessments and rankings obtained are found to be consistent with the inputs for the sites and the decision position, showing that the model can capture the effect of nonlinear input-output relations and is potentially useful for initial project screening. © 2018 The Authors. Published by Diamond Congress Ltd. Peer-review under responsibility of the scientific committee of the Creative Construction Conference 2018.