Intelligent replacement analysis using picture fuzzy sets: Defender-challenger comparison application

Replacement analysis is based on the principle that it may be more economical to retirement of an equipment earlier than its physical life. This replacement time, called the economic life, is usually calculated by annual cash flow analysis. These calculations made with deterministic estimations in classical analyzes are not realistic because they do not take into account the uncertainties in their estimations. Picture fuzzy sets (PFSs) introduced to the literature in recent years can provide a more detailed estimation by using the yes, abstain, no, and refusal degrees of the estimations. In this paper, the economic lives of defender and challenger, which are two alternatives of replacement analysis, are calculated using PFSs and a replacement decision was made. Estimates are made by three experts in the PF environment, and these estimates are aggregated by using PF aggregation operators. The optimistic, normal, and pessimistic estimations made with PFSs are converted into ordinary triangular fuzzy sets in the further stages of the analysis, and the economic life is determined for both the defender and the challenger by defuzzification of the triangular fuzzy numbers obtained with the center of gravity method. It has been revealed that the proposed fuzzy replacement analysis can be used as a decision support model for managers under uncertainty. A multi-expert comprehensive example has shown that PFSs can be used successfully in a real replacement application. The robustness of the given decisions by the replacement analysis is confirmed by a sensitivity analysis.