الفهرس | Only 14 pages are availabe for public view |
Abstract In this thesis, we present models of various repairable and unrepairable redundant systems with different types of standby in which the fuzzy approach is used to represent uncertain parameters. Also, we propose new methods for analyzing the fuzzy availability or fuzzy reliability of these redundant systems when the failure time and the repair time of their components follow different types of probability distributions. Furthermore, we introduce optimization models for two types of preventive maintenance policies: block replacement policy and age replacement policy and provide a technique to solve these optimization models when some of the models’ parameters are uncertain and represented by fuzzy numbers. Finally, numerical examples are introduced to illustrate the performance of all models if all fuzzy parameters are represented by the classical fuzzy, vague, or multi fuzzy sets estimated by statistical data. |