Papers by Surendra M. Gupta
A supply chain optimization approach for reverse logistics of end-of-life products
Page 1. Northeastern University ...
Reverse Supply Chain is described as an initiative that plays an important role in the global sup... more Reverse Supply Chain is described as an initiative that plays an important role in the global supply chain for those who seek environmentally responsible solutions for their end-of-life products. The relative economic and environmental benefits of reverse supply chain are influenced by costs and emissions during collection, transportation, recovery facilities, disassembly, recycling, remanufacturing, and disposal of unrecoverable components. The design of reverse supply chain network takes into account social, economic and environmental objectives. This paper addresses the design of reverse supply chain under the three common regulatory policies, strict carbon caps, carbon tax, and carbon cap-and-trade.Küresel tedarik zincirinde önemli bir rol oynayan tersine tedarik zinciri, ömrünü tamamlamış ürünler için çevreye karşı sorumlu çözümler arayanların bir girişimi olarak tanımlanmaktadır. Tersine tedarik zincirinin nispi ekonomik ve çevresel faydaları, toplama, nakliye, geri kazanım te...
Pricing strategy and competition for new and remanufactured products across generations
Journal of Remanufacturing, 2021
The e-waste from high-technology products is at the forefront of many studies that focus on reman... more The e-waste from high-technology products is at the forefront of many studies that focus on remanufacturing and selling end-of-use electronics. For the market of high-technology products, new commodities belonging to the early generation depreciate faster due to the rapid technology development and the challenge faced from remanufactured products belonging to the latest generation. The aim of this research is to develop pricing strategies for these items and understand how customer’s acceptance towards remanufactured products and the technology obsolescence of new products influence the pricing decisions. This study considers a pricing model in a system with a manufacturer, a remanufacturer, and a retailer. The manufacturer sells the new products belonging to the early generation to the retailer, while the remanufacturer sells the remanufactured product belonging to the latest generation. The customers, categorized into quality-conscious and technology-savvies, select one of the items based on the price and perceived value. The results of five game theory models (viz., Nash Equilibrium, Retailer-Stackelberg balancing power, Retailer-Stackelberg manufacturer lead, Manufacturer-Stackelberg balancing power, and Manufacturer-Stackelberg manufacturer lead) are compared. The impact of different value perceptions between quality-conscious customers and technology-savvies and each customer segment’s relative size are discussed in the five game theory models. The result shows that acting as a follower is a wise decision and suggests that the retailer, manufacturer, and remanufacturer coordinate by balancing their power.
Analysis of a just-in-time production system with supplier kanbans
As a consequence of environmental necessities, reuse of products has recently become an important... more As a consequence of environmental necessities, reuse of products has recently become an important issue for production and planning. Many companies are involved in retrieving used products, where they repair, refurbish and upgrade the products in order to sell them for profit. However, the regulations for many markets do not allow manufacturers to sell remanufactured products under the same pretence as new products. Therefore, companies are forced to differentiate both the recovery and the sales activities for the remanufactured products from that of the new products. In this paper, we study the impact of this differentiation. We particularly look at the feasibility of substituting one version of the product with the other in order to satisfy the demand. In the first phase of the study, we try to find optimal switching functions for substitution decisions using a Markov decision process. In the second phase, we define several control policies and compare them with respect to the exp...
In this study, we propose an intelli-gent automated disassembly cell for online (real time) selec... more In this study, we propose an intelli-gent automated disassembly cell for online (real time) selective disassembly. The cell is composed of an industrial robotic manipulator, a camera, range sensing and component segmentation visual algorithms. The cell prototype allows for robotic sensory-driven disassembly under uncertainty. An online genetic algorithm model for selective dis-assembly is also proposed for optimal and near/ optimal disassembly sequencing.
Logistics, 2021
The ever-increasing concerns of the growth in the volume of waste tires and new strict government... more The ever-increasing concerns of the growth in the volume of waste tires and new strict government legislations to reduce the environmental impact of the end-of-life (EOL) tires have increased interest among companies to design a sustainable and efficient closed-loop supply-chain (CLSC) network. In the real world, the CLSC network design is subject to a variety of uncertainties, such as random and fuzzy (epistemic) uncertainties. Designing a reliable and environmentally cautious CLSC with consideration of risks and the uncertainty of the parameters in the network is necessary for a successful supply-chain network. This study proposes a sustainable and environmentally cautious closed-loop supply-chain network for the tire industry, by considering several recovery options, including retreading, recycling, and energy recovery. This study aims to design and develop a robust multi-objective, multi-product, multi-echelon, multi-cycle, multi-capacity, green closed-loop supply-chain network ...
In this paper, we consider the disassembly-to-order (DTO) problem, where a variety of returned pr... more In this paper, we consider the disassembly-to-order (DTO) problem, where a variety of returned products are disassembled to fulfill the demand for specified numbers of components and materials. The main objective is to determine the optimal number of take-back EOL products for the DTO system that satisfy the desirable criteria of the system. Since the objectives of the DTO system always have different priorities and uncertain aspiration levels, weight-priority assignment and fuzzy sets theory have been applied to a multi-criteria decision-making approach to solve the problem. In addition, we consider product's deterioration that affects the product's yield rates (e.g., older products tend to have lower yield rates for usable components) and use heuristic procedure to transform the stochastic disassembly yields into their deterministic equivalents. The DTO plan is generated for multiple periods. A numerical example is also considered.
In this paper, we consider the disassembly-to-order (DTO) problem, where a variety of returned pr... more In this paper, we consider the disassembly-to-order (DTO) problem, where a variety of returned products are disassembled to fulfill the demand for specified numbers of components and materials. The objective is to determine the optimal numbers of returned products to disassemble so as to maximize profit and minimize costs. We model the DTO problem using a multi-criteria decision-making approach. Since the conditions of returned products are unknown, the yields from disassembly are considered to be stochastic. To solve the stochastic problem, we use one of the two heuristic approaches (viz., one-to-one approach or one-to-many approach) that converts the problem into a deterministic equivalent. We compare the performance of the two heuristic approaches using a case example.
Product disassembly takes place in remanufacturing, recycling, and disposal. The disassembly line... more Product disassembly takes place in remanufacturing, recycling, and disposal. The disassembly line is the best choice for automated disassembly, so it is essential that it be designed and balanced to work efficiently. A disassembly line faces many unique circumstances including: inventory problems because of the disparity between demands for parts and their yield, uncertainty in the returned product's structure and quality, and polluting or hazardous parts. The multi-criteria Disassembly Line Balancing Problem seeks to: provide a feasible disassembly sequence, minimize the number of workstations, minimize idle time, and balance the line (ensure similar idle times at each workstation) as well as addressing other, disassembly-specific concerns. However, finding the optimal balance is computationally intensive-due to factorial growth and exhaustive search quickly becoming prohibitively large-necessitating the use of heuristics. This paper demonstrates the mathematical foundations for the multiple objective Disassembly Line Balancing Problem using original mathematical formulae including those for determining upper and lower theoretical bounds. These formulae are essential in enabling a thorough efficacy analysis of a given part removal solution sequence. Because heuristics typically generate solutions that are less than optimal, metrics are needed to compare heuristics to each other or to a known best and worst case. In addition, one of the concerns when using heuristics is the idea that very little has been rigorously established in reference to their performance. Therefore, developing ways of explaining and predicting their performance is considered to be one of the most important challenges currently facing the fields of optimization and algorithms. In this paper, mathematical tools for quantitative measurement and graphical tools for qualitative analysis are developed and reviewed, focusing on analytical methodologies used in evaluating heuristic searches.
Disassembly line is crucial in recovering products in large quantities. It has recently gained a ... more Disassembly line is crucial in recovering products in large quantities. It has recently gained a lot of attention due to its role in efficiently recovering valuable materials, components, and subassemblies. Disassembly involves many challenges that further complicate the process. Recent research reported in the literature has focused on balancing disassembly lines. That means the time required for the work content at each station is balanced. However, the inventory generated at various stations may not be balanced. Additional inventory problems arise because of the disparity between the demand of certain components and the actual yield from the products. In this paper, we discuss these and other inventories issues to provide a better understanding of complications resulting from this and provide an approach to overcome them. A numerical example is considered to illustrate the approach.
In this paper, we focus on solving the disassembly-to-order (DTO) system, where end-of-life (EOL)... more In this paper, we focus on solving the disassembly-to-order (DTO) system, where end-of-life (EOL) products are taken back from last users to be disassembled to fulfill the demands of components and materials. The objective is to determine the optimal number of EOL products for the DTO system that satisfy the desirable criteria of the system. Frequently, decision makers (DM) find it difficult to specify the aspiration levels and weights relating to the priority of each objective of the DTO system. However, linear physical programming (LPP), which has key features to entirely remove the DM from the process of choosing weights and to handle the vagueness of aspiration levels, can be very suitable in such a situation. In this paper we generate the DTO plan for multiple periods using LPP. A numerical example is considered to illustrate the methodology.
Reverse logistics is a critical topic that has captured the attention of government, private enti... more Reverse logistics is a critical topic that has captured the attention of government, private entities and researchers in recent years. This increase in the concern was driven by current set of government regulations, increase of public awareness, and the attractive economic opportunities. As a result, many corporations have started to comprehend the importance of the recovery process and are taking serious steps in restructuring their supply chain processes to meet the new regulations such as limitations on waste disposal and recycling requirements [1]. Because of the unique problems associated with reverse supply chain and the complex nature of the reverse logistics activities, numerous studies have been carried out in this field. One of those crucial areas is inventory management of end-of-life (EOL) products. Previously, we have assumed deterministic data for demand, supply, and line yields when modeling the inventory problem along the disassembly line. In this paper, we model un...
Strategic planning of a supply chain primarily deals with the design (what products should be pro... more Strategic planning of a supply chain primarily deals with the design (what products should be processed/produced in what facilities etc) of the supply chain that is typically a long-range planning. Tactical planning involves the optimization of flow of goods and services across the supply chain and is typically a medium-range planning. In this paper, we present a single-phase unified approach, employing goal programming, for these two stages of planning of a Closed-Loop Supply Chain Network (CLSC). When solved, the model identifies simultaneously the most economical used-product to reprocess in the supply chain, the efficient production facilities and the right mix and quantity of goods to be transported across the supply chain. A numerical example is considered to illustrate the methodology.
PWien a product reaches its end-ojZlijZi (IEJOV, it can be reusea remanztRicturea recycled or dis... more PWien a product reaches its end-ojZlijZi (IEJOV, it can be reusea remanztRicturea recycled or disposed of Clf2en, in most oftheseproeesses, a certain levet ofdisassembly may be necessacy to separate components and materials, 7}herojbre, qptimal disassembly sequences are important to increase the qfiiciency of the disassembly. Since the complexity ofthe disassembly sequencing problem duamaticatly increases with the increase in the number ofprochtcts and component mpes, we propose an evotutionaty computationat approach to sotve it. specijically, we use Genetic Aigorithm ((}di to solve theproblem. A numericat exampte is considered to illustrate the use ofthis methodology.
The establishment of disassembly plants and the creation of product designs which specifically fa... more The establishment of disassembly plants and the creation of product designs which specifically facilitate disassembly are enabling manufacturers to carry out item segregation. Item segregation is defined as the separation from an assembly of a part or a group of parts by following a reverse assembly process. Once segregated, the items can be reused, recycled or discarded. However, there are operational problems associated with item segregation. Foremost amongst these are the lack of planning and scheduling mechanisms, difficulty in coping with reverse flow of materials, and item explosion. Despite the economic and environmental benefits of disassembly, researchers and practitioners are lagging behind in developing methodologies to address the operations and production planning and control issues associated with item segregation. This paper is aimed at addressing these issues. • Gupta, S. M. and Taleb, K., "Scheduling Disassembly", International Journal of Production Resear...
The establishment of disassembly plants and the creation of product designs which specifically fa... more The establishment of disassembly plants and the creation of product designs which specifically facilitate disassembly are enabling manufacturers to carry out item segregation. Item segregation is defined as the separation from an assembly of a part or a group of parts by following a reverse assembly process. Once segregated, the items can be reused, recycled or discarded. However, there are operational problems associated with item segregation. Foremost amongst these are the lack of planning and scheduling mechanisms, difficulty in coping with reverse flow of materials, and item explosion. Despite the economic and environmental benefits of disassembly, researchers and practitioners are lagging behind in developing methodologies to address the operations and production planning and control issues associated with item segregation. This paper is aimed at addressing these issues. • Gupta, S. M. and Taleb, K., "Scheduling Disassembly", International Journal of Production Resear...
There is a high level uncertainty associated with disassembly yield due to existence of unfunctio... more There is a high level uncertainty associated with disassembly yield due to existence of unfunctional and/or unneeded components in end of life products. Sensors embedded in critical components of a product can deal with this uncertainty by providing information on the type and condition of the components prior to disassembly. This study presents a quantitative assessment of the impact of sensor embedded products (SEPs) on the various performance measures of a kanban-controlled washing machine disassembly line. First, separate design of experiments studies based on orthogonal arrays are performed for the cases with and without SEPs. Then, the results of paired-t tests comparing two cases based on different performance measures are presented.
DEStech Transactions on Engineering and Technology Research, 2018
The design of a remanufacturing system that recovers sold products is needed to meet environmenta... more The design of a remanufacturing system that recovers sold products is needed to meet environmental objectives. However, to establish closed-loop supply chains for sustainability, it is necessary to consider not only environmental factors but also economic efficiency. By selling remanufactured products with prices lower than new products, market sizes may be expanded and firms may accrue higher profits. However, a cannibalization effect in which consumers who would have purchased new products instead purchase remanufactured products at lower prices can occur. The purpose of this study is to design a manufacturing-remanufacturing system to propose an optimal production planning and inventory control policy in consideration of the cannibalization effect. First, a time series model for the demand is constructed. Next, the economic efficiency and environmental impact of the system are evaluated by simulation experiments.
Responsible Manufacturing, 2019
In this problem, digitization facilitates an unprecedented degree of surveillance and quality con... more In this problem, digitization facilitates an unprecedented degree of surveillance and quality control along the point-to-point value chain from product design to end-of-life product recovery. This allows real-time monitoring of material flows from raw material acquisition to end-of-life product recovery by enabling autonomous data exchange. The manufacturer receives discarded products from multiple suppliers and communicate with returned devices to capture the data regarding their remaining useful life. With dynamic data collection during the useful life time of products, the uncertainty surrounding disassembly operations are reduced significantly. Final steps includes the manufacturer determining a recovery operation such as remanufacturing, reusing, recycling, or proper disposal based on the condition of each product.
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Papers by Surendra M. Gupta