Papers by Mehmet Kursat Oksuz
Integrated multi-manned disassembly line balancing problem with reverse supply chain design strategies by considering lot sizing, 2024
Due to strict governmental regulations, manufacturers have increasingly focused on recovering end... more Due to strict governmental regulations, manufacturers have increasingly focused on recovering end-of-life (EoL) products through disassembly lines, aiming to achieve economic benefits while addressing the environmental aspects of supply chain sustainability. Disassembly line balancing (DLB) has become a key challenge for enterprises seeking to perform environmentally conscious manufacturing as part of a closed-loop supply chain policy. Therefore, designing a sustainable closed-loop supply chain requires analyzing interrelated problems by focusing on strategic-, tactical-, and operational-level decisions simultaneously. This study introduces an integrated problem that addresses multi-manned DLB, lot sizing, and reverse supply chain (RSC) design problems. To mathematically represent the problem, a generic optimization model is developed to minimize overall costs, including station opening, inventory holding, shortage, transportation, and collection center/facility opening costs. This study addresses several research questions to explore the impact of distribution strategies (centralized and decentralized) on multi-manned DLB and lot size decisions within the context of reverse supply chain design.
Integrated optimization of facility location, casualty allocation and medical staff planning for post-disaster emergency response, 2023
Purpose-Disaster management and humanitarian logistics (HT) play crucial roles in large-scale eve... more Purpose-Disaster management and humanitarian logistics (HT) play crucial roles in large-scale events such as earthquakes, floods, hurricanes and tsunamis. Well-organized disaster response is crucial for effectively managing medical centres, staff allocation and casualty distribution during emergencies. To address this issue, this study aims to introduce a multi-objective stochastic programming model to enhance disaster preparedness and response, focusing on the critical first 72 h after earthquakes. The purpose is to optimize the allocation of resources, temporary medical centres and medical staff to save lives effectively. Design/methodology/approach-This study uses stochastic programming-based dynamic modelling and a discrete-time Markov Chain to address uncertainty. The model considers potential road and hospital damage and distance limits and introduces an a-reliability level for untreated casualties. It divides the initial 72 h into four periods to capture earthquake dynamics. Findings-Using a real case study in Istanbul's Kartal district, the model's effectiveness is demonstrated for earthquake scenarios. Key insights include optimal medical centre locations, required capacities, necessary medical staff and casualty allocation strategies, all vital for efficient disaster response within the critical first 72 h. Originality/value-This study innovates by integrating stochastic programming and dynamic modelling to tackle post-disaster medical response. The use of a Markov Chain for uncertain health conditions and focus on the immediate aftermath of earthquakes offer practical value. By optimizing resource allocation amid uncertainties, the study contributes significantly to disaster management and HT research.
Neural Computing and Applications
Unfortunately, the affiliation details of the third author, Alperen Bal has been published with i... more Unfortunately, the affiliation details of the third author, Alperen Bal has been published with incorrect information. The corrected affiliation information are given below:
Assembly lines are mass production system which improve productivity, flexibility and production ... more Assembly lines are mass production system which improve productivity, flexibility and production quality in industrial systems. Compared to traditional straight lines and parallel lines, U-shaped assembly lines have lots of advantages in terms of performance of workers and production system. Especially, by means of U-shaped layout, improved balancing of assembly lines can be achieved. Moreover, the implementation of Lean Manufacturing and Just in Time Production (JIT) systems entail U-shaped assembly line (Chiang, 2006). One-piece flow which significantly reduces manufacturing lead times is facilitated by this type of facility layout. Multi skilled workers can handle more than one machine in U-shaped assembly lines. An important issue in U-shaped line balancing problem is the consideration of human factors. There are a small number of studies about human factors in the literature. Some of the factors are the learning effect (Biskup, 1999; Toksari et al., 2008) and task time variability due to human factors (Becker and Scholl, 2006; Chiang and Urban, 2006). The purpose of this study is developing a methodology for balancing U-shaped assembly lines while considering the human factors to improve productivity of the production system. Keywords U-shaped line balancing, just in time production, human factors
Neural Computing and Applications
Comput. Ind. Eng., 2017
As the U-shaped assembly lines are concerned with manual assembly operations, workers’ performanc... more As the U-shaped assembly lines are concerned with manual assembly operations, workers’ performance plays a major role. However, the past studies assume that all workers can carry out all tasks with an equal performance level, and actual task times do not depend on the worker who performs it. On the other hand, this is unrealistic. In this study, maximization of the line efficiency for the U-shaped assembly line worker assignment and balancing problem by considering the worker performance is aimed. First, a non-linear model of the problem is formulated, and then it is linearized. Later, an Artificial Bee Colony Algorithm and a Genetic Algorithm are proposed to solve it, in short computational times. A hypothetical data set (Jackson, 1956), a real data set (Cevikcan et al., 2009) and data sets of assembly line worker assignment and balancing problem (Araujo et al., 2015) were solved by using the model and the meta-heuristics. The meta-heuristics were able to reach solutions that have ...
Effective material distribution is a vital issue to maintain the assembly lines’ operations. So, ... more Effective material distribution is a vital issue to maintain the assembly lines’ operations. So, coordination of the material supply to the assembly lines requires a system design that minimizes total material handling, inventory holding costs and prevents parts shortage. This is called the multi-commodity multi-vehicle material supply system design problem. To solve this, first, a Single-Vehicle Milk-run Mathematical Model is proposed. Then, a Matheuristic that iteratively employs the proposed model is developed to design a multi-vehicle in-plant milk-run system. The proposed methodology is validated by designing the milk-run system of a real washing machine assembly plant.
International Journal of Disaster Risk Reduction, 2019
Abstract Devastating effects of disasters and global crises on people increase the importance of ... more Abstract Devastating effects of disasters and global crises on people increase the importance of humanitarian logistics studies for pre and post-disaster stages. Location planning of Temporary Medical Centers/field hospitals is one of the most important problems for disaster response. We aimed to determine the location and number of temporary medical centers in case of disasters by considering the locations of the existing hospitals, casualty classification (triage), capacities of medical centers and possibilities of damage to the roads and hospitals. Besides, we aimed to assign different casualty classes to these medical centers for emergency medical response by considering the distances between disaster areas and medical centers. For this purpose, a two-stage stochastic programming model was developed. The proposed model finds an optimal TMC location solution while minimizing the total setup cost of the TMCs and the expected total transportation cost by considering casualty types, demand, possibilities of damage to the roads and hospitals, and distance between the disaster areas and the medical centers. In the model, α-reliability constraints for the expected number of unassigned casualties were also used. Besides, the model was reformulated without triage, in order to understand the impact of casualty classification on the solution of the problem. We performed a real case study for the district of Kartal expected to be widely damaged in the possible Istanbul earthquake, and a sensitivity analysis was made. The analysis of the results offer some managerial insights associated with the number of temporary medical centers’ needed, their locations, and additional hospital capacity requirements.
Assembly Automation, 2017
Purpose This paper aims to propose a combined methodology to help decision makers in evaluating a... more Purpose This paper aims to propose a combined methodology to help decision makers in evaluating and selecting the most effective part feeding system. Design/methodology/approach As a first step of the methodology, a hierarchical clustering analysis is applied to design a kitting or hybrid feeding system. Second, activity-based costing methodology is applied to determine which system is better according to their costs. Besides, sensitivity analysis is implemented to observe the behavior of the system in case of the takt time changes. Findings Using kitting systems purely can lead to problems because of the big and expensive parts in the mixed-model assembly systems. Therefore, the hybrid feeding policy can provide better solutions for such systems. Research limitations/implications A case study is conducted in a company and the most produced product of the company is considered to design the part feeding system. Results indicated that transportation cost has a large proportion on the...
Computers & Industrial Engineering, 2017
Abstract As the U-shaped assembly lines are concerned with manual assembly operations, workers’ p... more Abstract As the U-shaped assembly lines are concerned with manual assembly operations, workers’ performance plays a major role. However, the past studies assume that all workers can carry out all tasks with an equal performance level, and actual task times do not depend on the worker who performs it. On the other hand, this is unrealistic. In this study, maximization of the line efficiency for the U-shaped assembly line worker assignment and balancing problem by considering the worker performance is aimed. First, a non-linear model of the problem is formulated, and then it is linearized. Later, an Artificial Bee Colony Algorithm and a Genetic Algorithm are proposed to solve it, in short computational times. A hypothetical data set (Jackson, 1956), a real data set (Cevikcan et al., 2009) and data sets of assembly line worker assignment and balancing problem (Araujo et al., 2015) were solved by using the model and the meta-heuristics. The meta-heuristics were able to reach solutions that have equal line efficiency with the optimum solution found by the proposed mathematical model. The contribution of this study is that the mathematical model for the U-shaped line assembly line worker assignment and balancing type-E problem that considers the workers’ performance is formulated, and an Artificial Bee Colony Algorithm is proposed for the first time for this problem type.
International Journal of Disaster Risk Reduction, 2020
Devastating effects of disasters and global crises on people increase the importance of humanitar... more Devastating effects of disasters and global crises on people increase the importance of humanitarian logistics studies for pre and post-disaster stages. Location planning of Temporary Medical Centers/field hospitals is one of the most important problems for disaster response. We aimed to determine the location and number of temporary medical centers in case of disasters by considering the locations of the existing hospitals, casualty classification (triage), capacities of medical centers and possibilities of damage to the roads and hospitals. Besides, we aimed to assign different casualty classes to these medical centers for emergency medical response by considering the distances between disaster areas and medical centers. For this purpose, a two-stage stochastic programming model was developed. The proposed model finds an optimal TMC location solution while minimizing the total setup cost of the TMCs and the expected total transportation cost by considering casualty types, demand, possibilities of damage to the roads and hospitals, and distance between the disaster areas and the medical centers. In the model, α-reliability constraints for the expected number of unassigned casualties were also used. Besides, the model was reformulated without triage, in order to understand the impact of casualty classification on the solution of the problem. We performed a real case study for the district of Kartal expected to be widely damaged in the possible Istanbul earthquake, and a sensitivity analysis was made. The analysis of the results offer some managerial insights associated with the number of temporary medical centers’ needed, their locations, and additional hospital capacity requirements.
As the U-shaped assembly lines are concerned with manual assembly operations, workers’ performanc... more As the U-shaped assembly lines are concerned with manual assembly operations, workers’ performance plays a major role. However, the past studies assume that all workers can carry out all tasks with an equal performance level, and actual task times do not depend on the worker who performs it. On the other hand, this is unrealistic. In this study, maximization of the line efficiency for the U-shaped assembly line worker assignment and balancing problem by considering the worker performance is aimed. First, a non-linear model of the problem is formulated, and then it is linearized. Later, an Artificial Bee Colony Algorithm and a Genetic Algorithm are proposed to solve it, in short computational times. A hypothetical data set (Jackson, 1956), a real data set (Cevikcan et al., 2009) and data sets of assembly line worker assignment and balancing problem (Araújo et al., 2015) were solved by using the model and the meta-heuristics. The meta-heuristics were able to reach solutions that have equal line efficiency with the optimum solution found by the proposed mathematical model. The contribution of this study is that the mathematical model for the U-shaped line assembly line worker assignment and balancing type-E problem that considers the workers’ performance is formulated, and an Artificial Bee Colony Algorithm is proposed for the first time for this problem type.
Abstract
Purpose – This paper aims to propose a combined methodology to help decision makers in e... more Abstract
Purpose – This paper aims to propose a combined methodology to help decision makers in evaluating and selecting the most effective part feeding
system.
Design/methodology/approach – As a first step of the methodology, a hierarchical clustering analysis is applied to design a kitting or hybrid
feeding system. Second, activity-based costing methodology is applied to determine which system is better according to their costs. Besides,
sensitivity analysis is implemented to observe the behavior of the system in case of the takt time changes.
Findings – Using kitting systems purely can lead to problems because of the big and expensive parts in the mixed-model assembly systems.
Therefore, the hybrid feeding policy can provide better solutions for such systems.
Research limitations/implications – A case study is conducted in a company and the most produced product of the company is considered to
design the part feeding system. Results indicated that transportation cost has a large proportion on the total cost and the hybrid feeding policy may
be a good solution to reduce this cost.
Practical implications – The paper includes implications for the design of hybrid feeding systems in lean-based assembly lines. The proposed
methodology may be a practical tool for decision makers to design and decide on the part feeding policy.
Originality/value – Kitting design has not been studied yet to the best of the authors’ knowledge. Besides, there is no certain decision methodology
indicating which system is better. In this study, different methods are combined as a new methodology with the purpose of industrial
decision-making.
Keywords Lean manufacturing, Activity-based costing, Kitting, Hierarchical clustering analysis, Hybrid part feeding system, Internal logistics
Paper type Research paper
Purpose
This paper aims to propose a combined methodology to help decision makers in evaluating a... more Purpose
This paper aims to propose a combined methodology to help decision makers in evaluating and selecting the most effective part feeding system.
Design/methodology/approach
As a first step of the methodology, a hierarchical clustering analysis is applied to design a kitting or hybrid feeding system. Second, activity-based costing methodology is applied to determine which system is better according to their costs. Besides, sensitivity analysis is implemented to observe the behavior of the system in case of the takt time changes.
Findings
Using kitting systems purely can lead to problems because of the big and expensive parts in the mixed-model assembly systems. Therefore, the hybrid feeding policy can provide better solutions for such systems.
Research limitations/implications
A case study is conducted in a company and the most produced product of the company is considered to design the part feeding system. Results indicated that transportation cost has a large proportion on the total cost and the hybrid feeding policy may be a good solution to reduce this cost.
Practical implications
The paper includes implications for the design of hybrid feeding systems in lean-based assembly lines. The proposed methodology may be a practical tool for decision makers to design and decide on the part feeding policy.
Originality/value
Kitting design has not been studied yet to the best of the authors’ knowledge. Besides, there is no certain decision methodology indicating which system is better. In this study, different methods are combined as a new methodology with the purpose of industrial decision-making.
The p-median problem is one of the most well-known facility location problem and have several app... more The p-median problem is one of the most well-known facility location problem and have several applications in transportation, distribution, location of public, warehouses etc. The objective is to locate p facilities (medians) such that the sum of the distances from each demand point to its nearest facility is minimized. The p-median problem is well known to be NP-hard and several heuristics have been developed in the literature, but there are few applications of genetic algorithms for this problem. In this study, a new genetic algorithm approach to solve uncapacitated p-median problem is proposed. The parameters of the genetic algorithm are tuned using design of experiments approach. The proposed algorithm is tested on several instances of benchmark data set and evaluated with optimal solutions of the problems.
Assembly lines are mass production system which improve productivity, flexibility and production ... more Assembly lines are mass production system which improve productivity, flexibility and production quality in industrial systems. Compared to traditional straight lines and parallel lines, U-shaped assembly lines have lots of advantages in terms of performance of workers and production system. Especially, by means of U-shaped layout, improved balancing of assembly lines can be achieved. Moreover, the implementation of Lean Manufacturing and Just in Time Production (JIT) systems entail U-shaped assembly line (Chiang, 2006). One-piece flow which significantly reduces manufacturing lead times is facilitated by this type of facility layout. Multi skilled workers can handle more than one machine in U-shaped assembly lines. An important issue in U-shaped line balancing problem is the consideration of human factors. There are a small number of studies about human factors in the literature. Some of the factors are the learning effect (Biskup, 1999; Toksari et al., 2008) and task time variability due to human factors (Becker and Scholl, 2006; Chiang and Urban, 2006). The purpose of this study is developing a methodology for balancing U-shaped assembly lines while considering the human factors to improve productivity of the production system. Keywords U-shaped line balancing, just in time production, human factors
Thesis Chapters by Mehmet Kursat Oksuz
Worker performance must be considered in line balancing, because as a worker becomes more experie... more Worker performance must be considered in line balancing, because as a worker becomes more experienced in performing a specific task, in other words his/her cumulative production quantity increases, his/her task time per one piece of product decreases in a non-linear sense. Therefore, task times are not independent from workers’ performance. Another fact is, that every worker cannot perform every task at the same processing time. In addition, every worker cannot be able to perform every task in production systems. These facts can significantly cause actual task times differ from the presumed standard times.
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Papers by Mehmet Kursat Oksuz
Purpose – This paper aims to propose a combined methodology to help decision makers in evaluating and selecting the most effective part feeding
system.
Design/methodology/approach – As a first step of the methodology, a hierarchical clustering analysis is applied to design a kitting or hybrid
feeding system. Second, activity-based costing methodology is applied to determine which system is better according to their costs. Besides,
sensitivity analysis is implemented to observe the behavior of the system in case of the takt time changes.
Findings – Using kitting systems purely can lead to problems because of the big and expensive parts in the mixed-model assembly systems.
Therefore, the hybrid feeding policy can provide better solutions for such systems.
Research limitations/implications – A case study is conducted in a company and the most produced product of the company is considered to
design the part feeding system. Results indicated that transportation cost has a large proportion on the total cost and the hybrid feeding policy may
be a good solution to reduce this cost.
Practical implications – The paper includes implications for the design of hybrid feeding systems in lean-based assembly lines. The proposed
methodology may be a practical tool for decision makers to design and decide on the part feeding policy.
Originality/value – Kitting design has not been studied yet to the best of the authors’ knowledge. Besides, there is no certain decision methodology
indicating which system is better. In this study, different methods are combined as a new methodology with the purpose of industrial
decision-making.
Keywords Lean manufacturing, Activity-based costing, Kitting, Hierarchical clustering analysis, Hybrid part feeding system, Internal logistics
Paper type Research paper
This paper aims to propose a combined methodology to help decision makers in evaluating and selecting the most effective part feeding system.
Design/methodology/approach
As a first step of the methodology, a hierarchical clustering analysis is applied to design a kitting or hybrid feeding system. Second, activity-based costing methodology is applied to determine which system is better according to their costs. Besides, sensitivity analysis is implemented to observe the behavior of the system in case of the takt time changes.
Findings
Using kitting systems purely can lead to problems because of the big and expensive parts in the mixed-model assembly systems. Therefore, the hybrid feeding policy can provide better solutions for such systems.
Research limitations/implications
A case study is conducted in a company and the most produced product of the company is considered to design the part feeding system. Results indicated that transportation cost has a large proportion on the total cost and the hybrid feeding policy may be a good solution to reduce this cost.
Practical implications
The paper includes implications for the design of hybrid feeding systems in lean-based assembly lines. The proposed methodology may be a practical tool for decision makers to design and decide on the part feeding policy.
Originality/value
Kitting design has not been studied yet to the best of the authors’ knowledge. Besides, there is no certain decision methodology indicating which system is better. In this study, different methods are combined as a new methodology with the purpose of industrial decision-making.
Thesis Chapters by Mehmet Kursat Oksuz
Purpose – This paper aims to propose a combined methodology to help decision makers in evaluating and selecting the most effective part feeding
system.
Design/methodology/approach – As a first step of the methodology, a hierarchical clustering analysis is applied to design a kitting or hybrid
feeding system. Second, activity-based costing methodology is applied to determine which system is better according to their costs. Besides,
sensitivity analysis is implemented to observe the behavior of the system in case of the takt time changes.
Findings – Using kitting systems purely can lead to problems because of the big and expensive parts in the mixed-model assembly systems.
Therefore, the hybrid feeding policy can provide better solutions for such systems.
Research limitations/implications – A case study is conducted in a company and the most produced product of the company is considered to
design the part feeding system. Results indicated that transportation cost has a large proportion on the total cost and the hybrid feeding policy may
be a good solution to reduce this cost.
Practical implications – The paper includes implications for the design of hybrid feeding systems in lean-based assembly lines. The proposed
methodology may be a practical tool for decision makers to design and decide on the part feeding policy.
Originality/value – Kitting design has not been studied yet to the best of the authors’ knowledge. Besides, there is no certain decision methodology
indicating which system is better. In this study, different methods are combined as a new methodology with the purpose of industrial
decision-making.
Keywords Lean manufacturing, Activity-based costing, Kitting, Hierarchical clustering analysis, Hybrid part feeding system, Internal logistics
Paper type Research paper
This paper aims to propose a combined methodology to help decision makers in evaluating and selecting the most effective part feeding system.
Design/methodology/approach
As a first step of the methodology, a hierarchical clustering analysis is applied to design a kitting or hybrid feeding system. Second, activity-based costing methodology is applied to determine which system is better according to their costs. Besides, sensitivity analysis is implemented to observe the behavior of the system in case of the takt time changes.
Findings
Using kitting systems purely can lead to problems because of the big and expensive parts in the mixed-model assembly systems. Therefore, the hybrid feeding policy can provide better solutions for such systems.
Research limitations/implications
A case study is conducted in a company and the most produced product of the company is considered to design the part feeding system. Results indicated that transportation cost has a large proportion on the total cost and the hybrid feeding policy may be a good solution to reduce this cost.
Practical implications
The paper includes implications for the design of hybrid feeding systems in lean-based assembly lines. The proposed methodology may be a practical tool for decision makers to design and decide on the part feeding policy.
Originality/value
Kitting design has not been studied yet to the best of the authors’ knowledge. Besides, there is no certain decision methodology indicating which system is better. In this study, different methods are combined as a new methodology with the purpose of industrial decision-making.