Multi-level fuzzy comprehensive evaluation approach of construction crane and implementation

Construction cranes as major lifting equipments are widely used in infrastructure construction projects. With the number of manufacturers increasing and the series of products becoming more and more complete, the evaluation of their overall performances is becoming a focus point. Moreover, the comprehensive evaluation of the construction crane is a multi-level, multi-factor decision-making process. In this paper, on the basis of fully grasping cranes´ performances, a comprehensive index system of construction cranes is established by system engineering analysis method and Delphi method. To evaluate cranes´ performances by the proposed index system, a multi-level fuzzy comprehensive evaluation approach is put forward. In this approach, fuzzy numbers are used to quantize the qualitative indices, and combination weighting method based on fuzzy number judgement matrix is presented to determine the weights of indices. Based on analytic hierarchy process (AHP), fuzzy optimal model is built to implement comprehensive evaluation from low level to high level. As one kind of construction cranes, 6 types of truck cranes as an example are evaluated by the proposed index system and approach. The results actually reflect the development trend of truck cranes, and indicate that the indices can fully show the properties of the cranes. Therefore, the reasonability and availability of the proposed index system and approach are illustrated.