Presenting a Bi-objective Method in Location-allocation Problems Using Combinational Interval Full-ranking and Set Covering with Backup Model
Subject Areas : مدیریتMajede Kordjazi 1 , Abolfazl Kazemi 2
1 - M.Sc. Student, Department of Engineering, Qazvin Branch, Islamic Azad University, Qazvin, Iran.
2 - Assistant Professor, Department of Engineering, Qazvin Branch, Islamic Azad University, Qazvin, Iran
Keywords: Data envelopment analysis, ground and air ambulance services, Interval environment, Multi-criteria optimization,
Abstract :
Covering models have found many applications in a wide variety of real world problems, nevertheless some assumptions of covering models are not realistic enough, that’s why a general approach wouldn’t be able to answer needs of encountering varied aspects of real world considerations. Assumptions like unavailability of servers in emergency circumstances, postponing the process of serving customers, inevitable uncertainty in real world and evaluating more factors at the same time, are a sort of assumptions which covering models always face them but they are not able to find any answer to them. Therefore, how to deal with these sorts of assumptions has been reminded a big question. In this research, for facing unavailability, we address Backup covering and for facing uncertainty in input data, we propose Interval Full-ranking model. Furthermore, by combining backup covering and interval full-ranking models (also conceptions), not only we can save time and evaluate more factors like efficiency and cost simultaneously, but also covering considerations in real aspects are reachable. In final, we have solved the proposed model by using precise methods and Genetic revolutionary algorithm in small and large scales, respectively in order to analyze evaluate and compare the results. Results demonstrate appropriate performance of the proposed model despite simultaneous consideration of the mentioned assumptions and none of the assumptions are mutually exclusive.
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