فهرست نشریات علمی دسترسی آزاد ایران

Covering models have found many applications in a wide variety of real-world problems; nevertheless, some assumptions of covering models are not realistic enough. Accordingly, a general approach would not be able to answer the needs of encountering varied aspects of real-world considerations. Assumptions like the unavailability of servers, uncertainty, and evaluating more factors at the same time, are a sort of assumptions, with which covering models are always faced; however, these models are not able to find any answers for them. Therefore, how to deal with these sorts of assumptions has been always a big question. In this research, for facing unavailability and uncertainty in input data, backup covering and interval full-ranking model were addressed, respectively. Furthermore, by combining backup covering and interval full-ranking models (also conceptions), not only time was saved and more factors like efficiency and cost were simultaneously evaluated, but also covering considerations were reachable in real aspects.