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iii I hereby declare that all information in this document has been obtained and presented in accordance with academic rules and ethical conduct. I also declare that, as required by these rules and conduct, I have fully cited and referenced all material and results that are not original to this work. Name, Last Name : RAİFE MELTEM YETKİN Signature : iv ABSTRACT LOCATION ANALYSIS OF THE MOBILE/24 EMERGENCY SERVICE VEHICLES OF A CASE COMPANY Yetkin, Raife Meltem M.S., Department of Industrial Engineering Supervisor : Assist. Prof. Dr. Cem İyigün June 2012, 121 pages The aim of this study is planning the locations of emergency centers (ECs) as well as the number of vehicles in each EC of Corporation, Man Truck and Bus Group, to respond to the calls (arrival of the mobile/24 emergency service vehicle to the broken vehicle) within the desired time. The company aims to respond to the calls within 90 minutes. If the EC cannot respond to the calls within 90 minutes, they should be satisfied within 180 minutes. We propose a probabilistic programming approach to maximize the number of responded calls in 90 minutes while responding to all the calls in 180 minutes. The model determines the locations of the new ECs addition to the existing ones and also the number of vehicles assigned to those centers. The data source to this study is the emergency service calls of the company within February 2008 and December 2010. There are 30 ECs of the company distributed all over Turkey. By using the data, it is examined if the company can get closer to its target in responding to the calls with the current ECs. Necessary changes are proposed in the number and the locations of emergency centers for the desired target. Furthermore, several scenarios for targets with different quality service levels are generated and the effects of these parameters on the objective are observed. Keywords: logistics, mixed integer programming, quality service level v ÖZ VAKA ŞİRKETİNDE MOBİL/24 ACİL SERVİS ARAÇLARININ LOKASYON ANALİZİ Yetkin, Raife Meltem Yüksek Lisans, Endüstri Mühendisliği Bölümü Tez Yöneticisi: Yard. Doç. Dr. Cem İyigün Haziran 2012, 121 sayfa Bu çalışmanın amacı, Man Kamyon ve Otobüs Ticaret A.Ş.'nin acil servis merkezlerinin lokasyonlarını ve her bir merkezdeki mobil/24 acil servis araçlarının sayısını planlayarak, gelen aramalara istenilen süre içinde cevap vermesini (Mobil/24 acil servis aracının arızalı araç başına varmasını) sağlamaktır. Firmanın hedefi gelen aramalara 90 dakika içinde cevap vermektir. Eğer acil servis merkezi gelen aramalara 90 dakika içinde cevap veremezse, aramalar 180 dakika içinde cevaplanmalıdır. Firma tarafından daha önceden belirlenmiş olan kalite hizmet düzeylerine göre en fazla sayıda aramayı 90 dakika içinde ve gelen bütün aramaları 180 dakika içinde cevaplamak için olasılıksal programlama yaklaşımını öneriyoruz. Önerilen model önceki acil servis merkezlerine ek olarak açılacak yeni acil servis merkezlerinin lokasyonlarını ve bu merkezlere atanacak araçları belirlemektedir. Çalışmaya kaynak olan veri, f...

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The problem of central facilities location consists of designating m of n communities (m < n) as centers in such a way that the average distance or time travelled per person is a minimum. The average distance (or time) is equal to the sum of the products of population and miles (or minutes) travelled divided by the sum of the populations. Define a; = the population of the ith community si = the miles (or minutes) which individuals from the ith community S = the average of the distances (or times) travelled by all inmust travel to a center dividuals. The average distance is i=l Hence, minimizing the sum of population-miles minimizes the average distance.Alfred Weber pioneered Location Theory [I]. He considered the location of an industry between two resources and a single market where the criterion was minimization of transport cost. However, it is only in the last decade with the advent of mathematical programming and computer-aided computation that the problem has received real attention from the standpoint of research.Wersan, Quon and Charnes [2] presented one of the earliest of the modern considerations of locational problems. They located solid waste disposal sites to minimize haul costs in a metropolitan en-* Charles ReVelle and Ralph Swain are assistant professor and graduate fellow, respectively, in the

Backup coverage, the second coverage of a demand node, is suggested as a decision criterion in modelling the location of emergency services on a network. The efficient handling of stochastic demand by vehicles which can respond to only one call at a time may require backup coverage in areas of high demand as a means to maintain a more uniform level of service. This new criterion is applied in the context of the classic covering models, the Location Set Covering Problem and the Maximal Covering Location Problem. First coverage as defined in these models is traded off against backup coverage in the present work. Other efforts which incorporate additional levels of coverage are reviewed. We also show how to extend these models to third as well as subsequent coverage. Based on an example problem we show that significant levels of backup coverage may possibly be provided within a system without substantial loss of first coverage.government: emergency services, programming: integer, applications, set covering problems