A fuzzy logic approach to the selection of cranes

This paper presents a fuzzy logic approach to select the best crane type in a construction project from the main crane types, namely, mobile, tower and derrick cranes. Each factor of the project is classified as being dynamic or static according to whether the factor does or does not depend on the particular project. Linguistic information about the suitability of each crane type with respect to each factor of the project is translated into either fuzzy sets (for static factors) or fuzzy if–then rules (for dynamic factors). The fuzzy rules are then aggregated into a fuzzy relation between the space of factor property and the space of crane efficiency. In a particular project the experts describe the property as well as the relative importance of each factor. The rules are then fired using the max–min extension principle, and the resulting efficiencies are aggregated with their importance weights. The process identifies the best crane as the one with the highest expected overall efficiency.