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Book part
Publication date: 12 April 2012

Onder Ondemir and Surendra M. Gupta

Reverse supply chain (RSC) is an extension of the traditional supply chain (TSC) motivated by environmental requirements and economic incentives. TSC management deals with…

Abstract

Reverse supply chain (RSC) is an extension of the traditional supply chain (TSC) motivated by environmental requirements and economic incentives. TSC management deals with planning, executing, monitoring, and controlling a collection of organizations, activities, resources, people, technology, and information as the materials and products move from manufacturers to the consumers. Except for a short warranty period, TSC excludes most of the responsibilities toward the product beyond the point of sale. However, because of growing environmental awareness and regulations (e.g. product stewardship statute), TSC alone is no longer an adequate industrial practice. New regulations and public awareness have forced manufacturers to take responsibilities of products when they reach their end of lives. This has necessitated the creation of an infrastructure, known as RSC, which includes collection, transportation, and management of end-of-life products (EOLPs). The advantages of implementing RSC include the reduction in the use of virgin resources, the decrease in the materials sent to landfills and the cost savings stemming from the reuse of EOLPs, disassembled components, and recycled materials. TSC and RSC together represent a closed loop of materials flow. The whole system of organizations, activities, resources, people, technology, and information flowing in this closed loop is known as the closed-loop supply chain (CLSC).

In RSC, the management of EOLPs includes cleaning, disassembly, sorting, inspecting, and recovery or disposal. The recovery could take several forms depending on the condition of EOLPs, namely, product recovery (refurbishing, remanufacturing, repairing), component recovery (cannibalization), and material recovery (recycling). However, neither the quality nor the quantity of returning EOLPs is predictable. This unpredictable nature of RSC is what makes its management challenging and necessitates innovative management science solutions to control it.

In this chapter, we address the order-driven component and product recovery (ODCPR) problem for sensor-embedded products (SEPs) in an RSC. SEPs contain sensors and radio-frequency identification tags implanted in them at the time of their production to monitor their critical components throughout their lives. By facilitating data collection during product usage, these embedded sensors enable one to predict product/component failures and estimate the remaining life of components as the products reach their end of lives. In an ODCPR system, EOLPs are either cannibalized or refurbished. Refurbishment activities are carried out to meet the demand for products and may require reusable components. The purpose of cannibalization is to recover a limited number of reusable components for customers and internal use. Internal component demand stems from the component requirements in the refurbishment operation. It is assumed that the customers have specific remaining-life requirements on components and products. Therefore, the problem is to find the optimal subset and sequence of the EOLPs to cannibalize and refurbish so that (1) the remaining-life-based demands are satisfied while making sure that the necessary reusable components are extracted before attempting to refurbish an EOLP and (2) the total system cost is minimized. We show that the problem could be formulated as an integer nonlinear program. We then develop a hybrid genetic algorithm to solve the problem that is shown to provide excellent results. A numerical example is presented to illustrate the methodology.

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Applications of Management Science
Type: Book
ISBN: 978-1-78052-100-8

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Article
Publication date: 8 June 2021

Branimir Stojiljković, Ljubiša Vasov, Olja Čokorilo and Goran Vorotović

The purpose of this paper is to present novel recursive expressions for modelling the replacement costs of aircraft engine life-limited parts during shop visits to assist…

Abstract

Purpose

The purpose of this paper is to present novel recursive expressions for modelling the replacement costs of aircraft engine life-limited parts during shop visits to assist engine operators in both evaluating their decisions regarding the applied life-limited parts management strategies and tracking the replacement costs consistently throughout the life of the engine.

Design/methodology/approach

The replacement costs of aircraft engine life-limited parts are modelled analytically in this research, which strives to quantify the costs of used and unused lives of the replaced parts, incurred during engine shop visit events. Inputs for this model include the list price of life-limited parts, the replacement decisions made on all previous shop visits and the number of cycles the engine has operated at different thrust ratings on all previous operating intervals.

Findings

The average annual escalation rate of life-limited parts list prices was shown to range from 5% to 7%. The presented model is not only suitable for calculating the costs of used and unused lives of life-limited parts during past engine shop visit events but also for application in the life-limited parts replacement cost forecasting and optimisation models.

Originality/value

Uniquely derived recursive expressions represent the final result of the developed model which, to the authors’ knowledge, had not been studied elsewhere in the academic literature. The analysis of aircraft engine life-limited part list prices carried out to account for the average annual escalation rate enables the prediction of replacement costs during subsequent shop visits.

Details

Aircraft Engineering and Aerospace Technology, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1748-8842

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Article
Publication date: 29 May 2007

Evren Sahin, Mohamed Zied Babaï, Yves Dallery and Renaud Vaillant

The technology of time temperature integrators (TTI) is used to ensure the safety and quality of temperature sensitive goods such as food and drugs along their entire…

Abstract

Purpose

The technology of time temperature integrators (TTI) is used to ensure the safety and quality of temperature sensitive goods such as food and drugs along their entire lifespan. This work aims to provide a better understanding of potential benefits that can be expected from the use of TTIs in terms of supply chain improvement.

Design/methodology/approach

Based on the different types of information provided by TTIs: information on products' freshness and information on products' remaining shelf lives, the paper identifies qualitatively the benefits that would stem from each type of information.

Findings

A framework is built to evaluate the benefits, in terms of cost reduction and/or quality service improvement, that would stem from information provided by TTIs. Illustrative models are also developed in order to quantify some of these benefits.

Research limitations/implications

The coexistence on products' packaging of a printed use by date and a TTI device can be misleading for consumers. Besides, the benefits that supply chain actors will achieve by using TTIs will vary by product category and are dependent upon the level at which the TTI device is used. Further research and case studies have to be developed in order to bring further answers to these issues.

Practical implications

This paper is one of the first studies that helps companies in the food and the health care industry to better understand the benefits of using TTIs from an operations management point of view and to evaluate whether it can be advantageous to deploy this technology or not.

Originality/value

This work differs from investigations in literature in that it identifies exhaustively and qualitatively the benefits of TTIs and to give perspectives for quantitative models that can be developed to assess these benefits.

Details

The International Journal of Logistics Management, vol. 18 no. 1
Type: Research Article
ISSN: 0957-4093

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Article
Publication date: 15 March 2013

Jaekwon Chung and Dong Li

The purpose of this study is to compare the impact of multi‐period pricing, as an example of more dynamic pricing and discounting strategy with that of a present less…

Abstract

Purpose

The purpose of this study is to compare the impact of multi‐period pricing, as an example of more dynamic pricing and discounting strategy with that of a present less dynamic alternative on customer satisfaction and consumers' willingness to make trade‐offs between price and remaining shelf‐life.

Design/methodology/approach

The authors conducted interviews with three food retail managers in South Korea to gather practical information about the management of perishable foods, which informed the design of a survey in which consumers in South Korea were questioned about their perceptions of the two strategies, with respect to nine perishable food products in three categories. The data collected were analysed by one‐way ANOVA and the t‐test.

Findings

The findings of this research present an improved understanding of the impact of a multi‐period pricing strategy on consumer satisfaction and customer behaviour for perishable foods. The conclusions have the potential to significantly assist food retailers to understand the consumers' perspective on the benefits of a more dynamic pricing strategy.

Practical implications

The findings suggest that food retailers can enhance customer satisfaction by offering an earlier but lower discount, and increasing it as perishable food items approach their expiry date, rather than a higher discount when the expiry date is imminent.

Originality/value

The findings in this study are significant since they serve as the first step in measuring the value of dynamic pricing approaches that provide better trade‐off options between price and remaining shelf‐life from consumers' perspectives.

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Article
Publication date: 1 March 2004

Haritha Saranga

Opportunistic maintenance gives the maintenance crew an opportunity to replace or repair those items, which are found to be defective or needs replacement in the immediate…

Abstract

Opportunistic maintenance gives the maintenance crew an opportunity to replace or repair those items, which are found to be defective or needs replacement in the immediate future, during the maintenance of a sub‐system or a module. This paper tries to address the questions of how to decide whether a particular item needs opportunistic maintenance, and if so how cost effective the opportunistic maintenance is in comparison to a later grounding. These questions play an important role, especially in case of complex systems containing expensive items with hard lives and condition monitoring maintenance strategies. A systematic analysis of selection of components that require opportunistic maintenance is carried out, after which genetic algorithms are used to decide whether opportunistic maintenance is cost effective or not. A hypothetical example is used to describe the methodology for genetic algorithms.

Details

Journal of Quality in Maintenance Engineering, vol. 10 no. 1
Type: Research Article
ISSN: 1355-2511

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Article
Publication date: 24 September 2019

Christopher J. Shanahan, Roger D. Gibb, Johnson W. McRorie, Jose M. Brum and Mary E. Ritchey

Numerous randomized clinical studies have shown that psyllium fiber lowers serum cholesterol in patients with hyperlipidemia and is thus recognized by the US Food and Drug…

Abstract

Purpose

Numerous randomized clinical studies have shown that psyllium fiber lowers serum cholesterol in patients with hyperlipidemia and is thus recognized by the US Food and Drug Administration (FDA) as a dietary fiber that may help reduce the risk of coronary heart disease (CHD) by lowering cholesterol. The purpose of this paper is to assess the potential economic implications for health-care cost savings and quality of life productivity gains if the cholesterol-lowering effect of psyllium, consumed daily as a fiber supplement, could be applied to a broad at-risk population.

Design/methodology/approach

A cost-benefit analysis tool was used to examine evidence that the use of psyllium as a cholesterol-lowering agent can reduce overall CHD-attributed medical care service costs in the USA among those at high risk of experiencing disease-related events.

Findings

Results of the analysis showed that the potential net annual avoided medical care service costs and annual quality of life productivity gains among US adults 45 and older with low-density lipoprotein (LDL) cholesterol levels = 130 mg/dL could be up to an average of $870m per year from 2013 to 2020 if everyone in the target population used seven grams of soluble fiber from psyllium daily, corresponding to a net benefit-cost ratio of $1.19 savings in annual medical service cost and annual productivity gains per $1 spent on a psyllium regimen.

Originality/value

Thus, the use of psyllium fiber as a daily supplement could be recommended as a means to help control the risk for potentially costly cardiovascular-related medical events and to maximize the economic potential for an improved quality of life in adults 45 and older with LDL cholesterol levels =130 mg/dL.

Details

Nutrition & Food Science , vol. 50 no. 3
Type: Research Article
ISSN: 0034-6659

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Article
Publication date: 1 February 1991

LeRoy D. Brooks

A capital budgeting decision procedure appropriate for choosing the continuance, replacement, or abandonment of an asset‐in‐place is examined. The optimal replacement…

Abstract

A capital budgeting decision procedure appropriate for choosing the continuance, replacement, or abandonment of an asset‐in‐place is examined. The optimal replacement decision on an asset already in service requires simultaneous consideration of project life, project chaining, and possible abandonment points for both the asset‐in‐place and the replacement asset. The additional information required for the suggested procedure over the traditional replacement procedure is generally manageable and a practical solution procedure is feasible.

Details

Managerial Finance, vol. 17 no. 2/3
Type: Research Article
ISSN: 0307-4358

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Article
Publication date: 14 August 2017

Adrian Cubillo, Jeroen Vermeulen, Marcos Rodriguez de la Peña, Ignacio Collantes Casanova and Suresh Perinpanayagam

Integrated vehicle health management has been developed for several years in different industries, to be able to provide the required inputs to determine the optimal…

Abstract

Purpose

Integrated vehicle health management has been developed for several years in different industries, to be able to provide the required inputs to determine the optimal maintenance operations depending on the actual health status of the system. The purpose of this paper is to demonstrate the potential of a physics-based model (PbM) for prognostics with a real case study, based on the detection of incipient faults and estimate the remaining useful life of a planetary transmission of an aircraft system.

Design/methodology/approach

Most of the research in the area of health assessment algorithms has been focused on data-driven approaches that are not based on the knowledge of the physics of the system, while PbM approaches rely on the understanding of the system and the degradation mechanisms. A physics-based modelling approach to represent metal-metal contact and fatigue in the gears of the planetary transmission of an aircraft system is applied.

Findings

Both the failure mode caused by metal-metal contact as caused by fatigue in the gears is described. Furthermore, the real-time application that retrieves the results from the simulations to assess the health of the system is described. Finally the decision making that can be executed during flight in the aircraft is incorporated.

Originality/value

The paper proposes an innovative prognostics health management system that assesses two important failure modes of the planetary transmission that regulates the speed of the generators of an aircraft. The results from the models have been integrated in an application that emulates a real system in the aircraft and computes the remaining useful life in real time.

Details

International Journal of Structural Integrity, vol. 8 no. 4
Type: Research Article
ISSN: 1757-9864

Keywords

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Abstract

Details

Videogames, Libraries, and the Feedback Loop: Learning Beyond the Stacks
Type: Book
ISBN: 978-1-80071-505-9

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Book part
Publication date: 16 October 2007

Neil Bruce and Robert Halvorsen

One of the most contentious issues concerning benefit–cost analyses of environmental and other regulatory programs has been the valuation of reductions in mortality risks…

Abstract

One of the most contentious issues concerning benefit–cost analyses of environmental and other regulatory programs has been the valuation of reductions in mortality risks. The conceptual basis for most valuation exercises has been the value of a statistical life (VSL). However, despite decades of both theoretical and empirical research on the meaning and measurement of the VSL concept, there is no consensus concerning the validity of the results it produces in actual applications. In this paper, we review the development and application of the VSL approach and then propose what we believe to be a better way to value changes in mortality hazard.

Details

Research in Law and Economics
Type: Book
ISBN: 978-1-84950-455-3

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