Browsing by Author "Ornek, Mustafa Arslan"

Now showing 1 - 6 of 6

Citation - Scopus: 2
A GRASP Algorithm for Multi-objective Airport Gate Assignment Problem
(SPRINGER INTERNATIONAL PUBLISHING AG, 2022) Mert Paldrak; Mustafa Arslan Ornek; Paldrak, Mert; Ornek, Mustafa Arslan; DP Sakas; A Kavoura; P Tomaras
The assignment of flights to appropriate gates is a complex combinatorial optimization problem that airport managers have to deal with every day. It is an important decision-making problem involving multiple and conflicting objectives. Considering the different stakeholders of the problem a multi-objective airport gate assignment problem is proposed and formulated as a Binary Integer Programming Model. This paper studies two main objectives namely maximizing total flight-to-gate assignment utility and minimizing total flight conflict probability. Unlike most of the mathematical models presented in the literature Airport Gate Assignment Problem is considered an over-constraint problem where flight-to-gate eligibility apron safety and night-stand flight constraints are involved. As a solution methodology a Greedy Randomized Adaptive Search Procedure (GRASP) algorithm on over-constrained AGAP is proposed since the algorithm produces a series of good features such as intuitive greedy appeals and is trivial to be efficiently implemented on parallel processors like gates. The paper aims to demonstrate the efficiency of the proposed solution methodology concerning determined objective functions.
A Multi-objective Approach to Flight Scheduling and Fleet Assignment in Hub Network
(Springer, 2025) Melis Tan Tacoglu; Mustafa Arslan Ornek; Cemalettin Öztürk; Ornek, Mustafa Arslan; Ozturk, Cemalettin; Tacoglu, Melis Tan
The hub-and-spoke (HS) network is a widely used business strategy by airlines to optimize their operations and increase their reach by connecting multiple destinations through a central hub and the majority of the passengers are transit passengers. The airline schedule planning process starts with the flight scheduling problem (FSP) to generate a timetable in advance of six months. Then the fleet assignment problem (FAP) is examined to determine aircraft types. This sequential solution approach causes suboptimal solutions and the schedule must be adjusted to increased demand. Due to the complexity of this problem this study focuses specifically on incremental schedule design with one hub two-flight leg network. This study presents a Multi-Objective Mixed Integer Programming Model for integrated FSP and FAP to adjust the generated timetable with launching new flights. Two solution approaches are proposed to decide the new proposed flight’s time aircraft type and passenger assignment: the Weighted Goal Programming Model (WGPM) and the Lexicographic Goal Programming Model (LGPM). This study shows that there is a conflicting relationship between cost and C02 emissions in the flight scheduling process. If carbon dioxide emissions are prioritized airlines need to schedule more flights with small-capacity aircraft. © 2025 Elsevier B.V. All rights reserved.
A Survey on Optimization Problems in the Airline Industry and Airports
(SPRINGER INTERNATIONAL PUBLISHING AG, 2024) Mert Paldrak; Melis Tan Tacoglu; Mustafa Arslan Ornek; Paldrak, Mert; Ornek, Mustafa Arslan; Tacoglu, Melis Tan; C Kahraman; SC Onar; S Cebi; B Oztaysi; AC Tolga; IU Sari
In response to the rapid growth in air transportation demand the methods to manage allocate and efficiently use scarce resources in the airport play a vital role in improving the efficiency of the air transportation system. Due to the limited infrastructure of hub-and-spoke airports which is influenced by many factors the chief goal of the airline industry and airport management is to utilize such resources as check-in desks departure lounges bridge-equipped gates aircraft stands baggage carousels staff and equipment. Based on the mobility of the resources in the airports there are two types of problems in the airline industry and airports namely mobile and immobile resource optimization problems. The crew optimization problems are mobile resource optimization problems whereas airport gate assignment counter assignment problems and carousel optimization problems are immobile resource optimization problems in airports. Considering the problems classified based on the mobility of the resources this paper aims to present a survey of optimization problems in the aviation industry explaining the interplay and relationship between these problems along with modeling techniques and proposed solutions to this individual problem.
Citation - WoS: 2
Citation - Scopus: 2
A two-stage real world serial batching scheduling problem: a case study
(TAYLOR & FRANCIS LTD, 2024) Sadik Serhat Karakutuk; Sener Akpinar; Mustafa Arslan Ornek; Akpinar, Sener; Ornek, Mustafa Arslan; Karakutuk, Sadik Serhat
This paper concerns a real-life production management problem composed of two stages which includes interdependent batch scheduling problems. Moreover both stages require setup operations at the beginning and between the subsequent batches. From the optimisation point of view this production management problem is complying with customers' deadlines and hence minimising total lateness. To achieve this objective the production planner must identify optimum or near-optimum batch schedules for both stages. Correspondingly this paper aims to develop a methodology to manage the related production problem as accurately as possible. We formulate an optimisation model that employs the mathematical programming method in line with this. Afterwards an algorithmic proposal based on the simulated annealing algorithm is also developed to solve the problem in realistic sizes. The computational capabilities of the developed model and the algorithm are evaluated on the randomly generated problem sets. A direct comparison between the mathematical model and the algorithm shows how efficiently the proposed algorithm solves real-world problems. Also computational results indicate that the proposed algorithm satisfactorily solves the related real-world batch scheduling problem.
Genetic Algorithm and Mathematical Modelling for Integrated Schedule Design and Fleet Assignment at a Mega-Hub
(Multidisciplinary Digital Publishing Institute (MDPI), 2025) Melis Tan Tacoglu; Mustafa Arslan Ornek; Yigit Kazancoglu; Tan Tacoglu, Melis; Ornek, Mustafa Arslan; Tacoglu, Melis Tan; Kazancoglu, Yigit
Airline networks are becoming increasingly complex particularly at mega-hub airports characterized by high transit volumes. Effective schedule design and fleet assignment are critical for an airline as they directly influence passenger connectivity and profitability. This study addresses the challenge of introducing a new route from a mega-hub to a new destination while maintaining the existing flight network and leveraging arrivals from spoke airports to ensure connectivity. First a mixed-integer nonlinear mathematical model was formulated to produce a global optimal solution at a lower time granularity but it became computationally intractable at higher granularities due to the exponential growth in constraints and variables. Second a genetic algorithm (GA) was employed to demonstrate scalability and flexibility delivering near-optimal high-granularity schedules with significantly reduced computational time. Empirical validation using real-world data from 37 spoke airports revealed that while the exact model minimized waiting times and maximized profit at lower granularity the GA provided nearly comparable profit at higher granularity. These findings guide airline managers seeking to optimize passenger connectivity and cost efficiency in competitive global markets. © 2025 Elsevier B.V. All rights reserved.
Mathematical Modeling Approach for Flight Timetable Generation with Return Flights and Airport Slot Capacity
(Springer International Publishing AG, 2025) Tan Tacoglu, Melis; Ornek, Mustafa Arslan; Tacoglul, Melis Tan; Kazancoglu, Yigit
This paper aims to generate a flight timetable between the hub and spokes, taking into account transit passenger waiting time at the hub and spokes in the pure-hub-and-spoke network. A non-linear mathematical model is developed to generate the flight timetable considering return flights, airport slot capacity, and passenger waiting time for the mega hub network. The results show that the decision to either rotate an arriving aircraft or dispatch a different aircraft has a crucial impact on passenger waiting times at both the destination and the hub. The aggregated demand at the hub, rather than individual origin-destination demand, plays a key role in determining the optimal schedule.