Funda Serifoglu | Istanbul Bilgi University (original) (raw)
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Papers by Funda Serifoglu
This study focuses on the client-contractor bargaining problem in the context of multi mode resou... more This study focuses on the client-contractor bargaining problem in the context of multi mode resource constrained project scheduling. The bargaining objective is to maximize the bargaining function comprised of the individual NPV maximizing objectives of both the client and the contractor. Tabu Search and Simulated Annealing are proposed as solution procedures.
Computers & Operations Research, 2011
Supply Chain Management: An International Journal, 2010
Home > Supply Chain Management: An International Journal > Volume 1... more Home > Supply Chain Management: An International Journal > Volume 15 issue 1 > Exploring reverse supply chain management practices... ... Icon: Abstract. Icon: Backfiles. Icon: Print. Icon: Reprints & permissions. ... This research was fully supported by the Scientific and ...
Naval Research …, Jan 1, 2009
The client-contractor bargaining problem addressed here is in the context of a multi-mode resourc... more The client-contractor bargaining problem addressed here is in the context of a multi-mode resource constrained project scheduling problem with discounted cash flows, which is formulated as a progress payments model. In this model, the contractor receives payments from the client at predetermined regular time intervals. The last payment is paid at the first predetermined payment point right after project completion. The second payment model considered in this paper is the one with payments at activity completions. The project is represented on an Activity-on-Node (AON) project network. Activity durations are assumed to be deterministic. The project duration is bounded from above by a deadline imposed by the client, which constitutes a hard constraint. The bargaining objective is to maximize the bargaining objective function comprised of the objectives of both the client and the contractor. The bargaining objective function is expected to reflect the two-party nature of the problem environment and seeks a compromise between the client and the contractor. The bargaining power concept is introduced into the problem by the bargaining power weights used in the bargaining objective function. Simulated annealing algorithm and genetic algorithm approaches are proposed as solution procedures. The proposed solution methods are tested with respect to solution quality and solution times. Sensitivity analyses are conducted among different parameters used in the model, namely the profit margin, the discount rate, and the bargaining power weights. Table 3. Average percent deviations from the optimal solutions and t-test results. % Deviations SA GA t-test (P = 0.05)
Computers & Operations Research, 2008
This paper aims to contribute to the recent research efforts to bridge the gap between the theory... more This paper aims to contribute to the recent research efforts to bridge the gap between the theory and the practice of scheduling by modelizing a realistic manufacturing environment and analyzing the effect of the inclusion of several characteristics in the problem formulation. There are several constraints and characteristics that affect the scheduling operations at companies. While these constraints are many times tackled in the literature, they are seldom considered together inside the same problem formulation. We propose a formulation along with a mixed integer modelization and some heuristics for the problem of scheduling n jobs on m stages where at each stage we have a known number of unrelated machines. The jobs might skip stages and, therefore, we have what we call a hybrid flexible flowshop problem. We also consider per machine sequence-dependent setup times which can be anticipatory and non-anticipatory along with machine lags, release dates for machines, machine eligibility and precedence relationships among jobs. Manufacturing environments like this appear in sectors like food processing, ceramic tile manufacturing and several others. The optimization criterion considered is the minimization of the makespan. The MIP model and the heuristics proposed are tested against a comprehensive benchmark and the results evaluated by advanced statistical tools that make use of decision trees and experimental designs. The results allow us to identify the constraints that increase the difficulty. ᭧
Citeseer
A genetic algorithm is developed to schedule multi-processor tasks in a multistage hybrid flowsho... more A genetic algorithm is developed to schedule multi-processor tasks in a multistage hybrid flowshop environment. The objective is to minimize the makespan, i.e. the completion of the task of the lastly scheduled job in the last stage. The genetic algorithm is tested against a lower bound from literature on a test bed comprising of 400 problems with up to 100 jobs, 10 stages, and up to 5 processors on each stage.
... Kılıç M1, Ulusoy G2, and Sivrikaya Şerifoğlu F3 ... Resource contrained scheduling in project... more ... Kılıç M1, Ulusoy G2, and Sivrikaya Şerifoğlu F3 ... Resource contrained scheduling in project planning., in Yöneylem Araştırması Halim Doğrusöz'e Armağan (Erkip, N. and M. Köksalan, eds); METU Basım Đşliği, Ankara. f1 f2 H ...
This study focuses on the client-contractor bargaining problem in the context of multi mode resou... more This study focuses on the client-contractor bargaining problem in the context of multi mode resource constrained project scheduling. The bargaining objective is to maximize the bargaining function comprised of the individual NPV maximizing objectives of both the client and the contractor. Tabu Search and Simulated Annealing are proposed as solution procedures.
Computers & Operations Research, 2011
Supply Chain Management: An International Journal, 2010
Home > Supply Chain Management: An International Journal > Volume 1... more Home > Supply Chain Management: An International Journal > Volume 15 issue 1 > Exploring reverse supply chain management practices... ... Icon: Abstract. Icon: Backfiles. Icon: Print. Icon: Reprints & permissions. ... This research was fully supported by the Scientific and ...
Naval Research …, Jan 1, 2009
The client-contractor bargaining problem addressed here is in the context of a multi-mode resourc... more The client-contractor bargaining problem addressed here is in the context of a multi-mode resource constrained project scheduling problem with discounted cash flows, which is formulated as a progress payments model. In this model, the contractor receives payments from the client at predetermined regular time intervals. The last payment is paid at the first predetermined payment point right after project completion. The second payment model considered in this paper is the one with payments at activity completions. The project is represented on an Activity-on-Node (AON) project network. Activity durations are assumed to be deterministic. The project duration is bounded from above by a deadline imposed by the client, which constitutes a hard constraint. The bargaining objective is to maximize the bargaining objective function comprised of the objectives of both the client and the contractor. The bargaining objective function is expected to reflect the two-party nature of the problem environment and seeks a compromise between the client and the contractor. The bargaining power concept is introduced into the problem by the bargaining power weights used in the bargaining objective function. Simulated annealing algorithm and genetic algorithm approaches are proposed as solution procedures. The proposed solution methods are tested with respect to solution quality and solution times. Sensitivity analyses are conducted among different parameters used in the model, namely the profit margin, the discount rate, and the bargaining power weights. Table 3. Average percent deviations from the optimal solutions and t-test results. % Deviations SA GA t-test (P = 0.05)
Computers & Operations Research, 2008
This paper aims to contribute to the recent research efforts to bridge the gap between the theory... more This paper aims to contribute to the recent research efforts to bridge the gap between the theory and the practice of scheduling by modelizing a realistic manufacturing environment and analyzing the effect of the inclusion of several characteristics in the problem formulation. There are several constraints and characteristics that affect the scheduling operations at companies. While these constraints are many times tackled in the literature, they are seldom considered together inside the same problem formulation. We propose a formulation along with a mixed integer modelization and some heuristics for the problem of scheduling n jobs on m stages where at each stage we have a known number of unrelated machines. The jobs might skip stages and, therefore, we have what we call a hybrid flexible flowshop problem. We also consider per machine sequence-dependent setup times which can be anticipatory and non-anticipatory along with machine lags, release dates for machines, machine eligibility and precedence relationships among jobs. Manufacturing environments like this appear in sectors like food processing, ceramic tile manufacturing and several others. The optimization criterion considered is the minimization of the makespan. The MIP model and the heuristics proposed are tested against a comprehensive benchmark and the results evaluated by advanced statistical tools that make use of decision trees and experimental designs. The results allow us to identify the constraints that increase the difficulty. ᭧
Citeseer
A genetic algorithm is developed to schedule multi-processor tasks in a multistage hybrid flowsho... more A genetic algorithm is developed to schedule multi-processor tasks in a multistage hybrid flowshop environment. The objective is to minimize the makespan, i.e. the completion of the task of the lastly scheduled job in the last stage. The genetic algorithm is tested against a lower bound from literature on a test bed comprising of 400 problems with up to 100 jobs, 10 stages, and up to 5 processors on each stage.
... Kılıç M1, Ulusoy G2, and Sivrikaya Şerifoğlu F3 ... Resource contrained scheduling in project... more ... Kılıç M1, Ulusoy G2, and Sivrikaya Şerifoğlu F3 ... Resource contrained scheduling in project planning., in Yöneylem Araştırması Halim Doğrusöz'e Armağan (Erkip, N. and M. Köksalan, eds); METU Basım Đşliği, Ankara. f1 f2 H ...