Browsing by Author "Ozkarahan I."

Now showing 1 - 4 of 4
  • No Thumbnail Available
    Item
    A constraint programming heuristic for a heterogeneous vehicle routing problem with split deliveries
    (Bellwether Publishing, Ltd., 2010) Ozfirat P.M.; Ozkarahan I.
    This article considers fresh goods distribution of a retail chain store in Turkey. The problem is formulated as a vehicle routing problem with a heterogeneous fleet for which no exact algorithm has ever been designed to solve it. A fast and effective algorithm based on constraint programming is proposed for the solution. The procedure is tested on some of the benchmark problems in literature. The real-life case is first solved assuming that delivery of a customer cannot be split between vehicles. Then it is resolved considering split deliveries. Solutions of both strategies are compared with the current performance of the firm to determine a distribution strategy. Results indicate considerable improvement in the performance of the firm.
  • No Thumbnail Available
    Item
    Parallel machine scheduling with additional resources: Notation, classification, models and solution methods
    (Elsevier B.V., 2013) Edis E.B.; Oguz C.; Ozkarahan I.
    Majority of parallel machine scheduling studies consider machine as the only resource. However, in most real-life manufacturing environments, jobs may require additional resources, such as automated guided vehicles, machine operators, tools, pallets, dies, and industrial robots, for their handling and processing. This paper presents a review and discussion of studies on the parallel machine scheduling problems with additional resources. Papers are surveyed in five main categories: machine environment, additional resource, objective functions, complexity results and solution methods, and other important issues. The strengths and weaknesses of the literature together with open areas for future studies are also emphasized. Finally, extensions of integer programming models for two main classes of related problems are given and conclusions are drawn based on computational studies. © 2013 Elsevier B.V. All rights reserved.
  • No Thumbnail Available
    Item
    Operating room management in health care: Operations research and artificial intelligence approaches
    (IGI Global, 2013) Ozkarahan I.; Edis E.B.; Ozfirat P.M.
    Surgical units are generally the most costly and least utilized units of hospitals. In order to provide higher utilization rates of surgical units, scheduling of operating rooms should be done effectively. Inefficient or inaccurate scheduling of operating room time often results in delays of surgery or cancellations of procedures, which are costly to the patient and the hospital. Therefore, operating room scheduling and management problems have been an important area of research both for operations researchers and artificial intelligence researchers since the 1960s. In this chapter, the operations research and artificial intelligence solutions developed for operating room scheduling problems in the operational level are examined and discussed. The studies are classified according to the approaches employed. The chapter is aimed to be helpful for researchers who are willing to make contributions in this area as well as the practitioners who are looking for efficient and effective ways to handle the operating room management problem of their own. © 2013 by IGI Global. All rights reserved.
  • No Thumbnail Available
    Item
    Operating room management in health care: Operations research and artificial intelligence approaches
    (IGI Global, 2014) Ozkarahan I.; Edis E.B.; Ozfirat P.M.
    Surgical units are generally the most costly and least utilized units of hospitals. In order to provide higher utilization rates of surgical units, scheduling of operating rooms should be done effectively. Inefficient or inaccurate scheduling of operating room time often results in delays of surgery or cancellations of procedures, which are costly to the patient and the hospital. Therefore, operating room scheduling and management problems have been an important area of research both for operations researchers and artificial intelligence researchers since the 1960s. In this chapter, the operations research and artificial intelligence solutions developed for operating room scheduling problems in the operational level are examined and discussed. The studies are classified according to the approaches employed. The chapter is aimed to be helpful for researchers who are willing to make contributions in this area as well as the practitioners who are looking for efficient and effective ways to handle the operating room management problem of their own. © 2015 by IGI Global. All rights reserved.