Internal Supply-chain Competition In Remanufacturing: Operations Strategies, Performance And Environmental Effects

This paper investigates the competitive and environmental effects of different operations strategies of original equipment manufacturers (OEMs) and semi-independent remanufacturers, which simultaneously cooperate and compete in different stages of a closed-loop supply chain. In particular, a co-opetitive situation, in which remanufacturing is undertaken only by retailers while the OEMs' role is restricted to recycling is considered. After adopting a resource-based perspective of competition, investigations are accomplished using system dynamics simulation modelling. The results of simulations indicate that, in the long run, OEMs, regardless of the operation strategy they adopt, are unable to (re)capture the market gained by the remanufacturers. However, some of these strategies contribute to the improvement of the environmental performance of the entire supply chain

Optimal Decision Making for Capacitated Reverse Logistics Networks with Quality Variations

Increasing concerns about the environmental impact of production, product take-back laws and dwindling natural resources have heightened the need to address the impact of disposing end-of-life (EOL) products. To cope this challenge, manufacturers have integrated reverse logistics into their supply chain or chosen to outsource product recovery activities to third party firms. The uncertain quality of returns as well as uncertainty in return flow limit the effectiveness of planning, control and monitoring of reverse logistics networks. In addition, there are different recovery routes for each returned product such as reuse, repair, disassembling, remanufacturing and recycling. To determine the most profitable option for EOL product management, remanufacturers must consider the quality of returns and other limitations such as inventory size, demand and quantity of returns. The work in this dissertation addresses these pertinent aspects using two models that have been motivated by two remanufacturing facilities whereby there are uncertainties in the quality and quantity of return and capacitated inventories. In the first case, a disposition decision making model is developed for a remanufacturing process in which the inventory capacity of recoverable returns is limited and where there\u27s a constant demand to be met, for remanufactured products that meet a minimum quality threshold. It is assumed that the quality of returns is uncertain and remanufacturing cost is dependent on the quality grade. In this model, remanufacturing takes place when there is demand for remanufactured products. Accepted returns that meet the minimum quality threshold undergo the remanufacturing processes, and any unacceptable returns are salvaged. A continuous time Markov chain (CTMC) is presented as the modeling approach. The Matrix-Geometric solution methodology is applied to evaluate several key performance metrics for this system, to result in the optimal disposition policy. The numerical study shows an intricate trade-off between the acceptable quality threshold value and the recoverable product inventory capacity. Particularly, there are periodic system starvation whenever there is a mis-match between these two system metrics. In addition, the sensitivity analysis indicates that changes to the demand rate for remanufactured products necessitates the need to re-evaluate the existing system configuration. In the second case, a general framework is presented for a third party remanufacturer, where the remanufacturer has the alternative of salvaging EOL products and supplying parts to external suppliers, or remanufacture the disassembled parts to \u27as new\u27 conditions. The remanufacturing processes of reusable products and parts is studied in the context of other process variables such as the cost and demand of remanufactured products and parts. The goal of this model is to determine the return quality thresholds for a multi-product, multi-period remanufacturing setting. The problem is formulated as a mixed integer non-linear programming (MINLP) problem, which involves a discretization technique that turns the problem turns into a quadratic mixed integer programming (QMIP) problem. Finally, a numerical analysis using a personal computer (PC) remanufacturing facility data is used to test the extent to which the minimum acceptance quality threshold is dependent on the inventory level capacities of the EOL product management sites, varying operational costs and the upper bound of disposal rate

Advancing the circular economy Reverse logistics and remanufacturing of dieselparticle filters

The Circular economy (CE) is an economic system created as an alternative to the unsustainable linear economy. CE and its business models aims to deal with the challenges as resource depletion, waste creation and over consumption by closing the material loop. CE is today practiced using different business models. One such business model is remanufacturing. A business model that has gained a lot of attention in different industries, especially in the vehicle industry. The vehicle industry, is an industry that use a lot of materials, and have a huge impact on the environment, and with the use of remanufacturing, it accomplishes to reduce material usage and decrease environmental impacts. This creates the need to look further into the remanufacturing of vehicle parts, and the focus of this thesis is remanufacturing of more diesel particle filters in the Swedish market. The thesis involves three actors, Volvo Cars, Stena Recycling Sverige, and UBD Cleantech. The study originates from Giab godsinlösen Nordic AB, that had the assumption of that there are valuable streams of diesel particle filters that currently are not collected but could be collected for remanufacturing. This study goes through literature of different concepts with key concepts of drivers and barriers for remanufacturing in the vehicle sector. This to identify what drivers and barriers there are for remanufacturing in the vehicle sector. This is followed by interviews with representatives at Stena Recycling Sverige, Volvo Cars and UBD Cleantech to examine the possibilities to collect more diesel particle filters for remanufacturing. The findings show that there are established cooperations that could enable remanufacturing of more diesel particle filters. But barriers such as the customer demand, storing and sorting can be a difficulty to overcome. However, drivers such as the environmental incentive and laws and regulation is positive for it. The conclusion and recommendations suggest further research in evaluating the quality of the filters, and the customer demand for them, but also to research other actors such as car dismantlers and car workshops that are related to the collection of diesel particle filters

Performance Evaluation of a Reverse Logistics Enterprise - An Agent-Based Modelling Approach

Reverse Logistics (RL) has been applied in many industries and sectors ever since its conception. Unlike Forward Logistics retracing consumer goods from the point of consumption to the point of inception is not a well-studied process. It involves many uncertainties such as time, quality and quantity of return. It is important to address these uncertainties to meet the economic, ecological and social challenges. The returned products can be remanufactured, can have parts harvested, or can be disposed safely. It is important to implement these activities in a cost-effective manner. The aim of this research is to measure the performance of the RL enterprise with the help of an Agent-based Modeling technique. The major entities in the RL network are considered as Agents that can act independently. There are several different agents: Collector Agent, Sorting-Cum-Reuse Agent, Remanufacturing Agent, Recycler Agent, Supplier Agent, and Distributor Agent. The individual performances of each agent are measured and recommendations are given to improve their performance, leading to the enhancement of the total performance of the RL enterprise. The solution approach is applied to a case study involving cell-phone remanufacturing

Improving Demand and Supply Balance in a Closed-Loop Supply Chain : A Case Study in a Dynamic Reuse Spare Part Business

Many companies have adopted closed-loop supply chain (CLSC) systems in pursuit of greener operations through reuse product offering. Contrary to traditional forward supply chains, CLSCs combine both supply chain directions, forward and reverse. As well, the CLSC incorpo-rates circular manufacturing process into the loop, such as repairing, refurbishing, or reman-ufacturing. The combination of multiple simultaneous processes leads to added complexity in a circular system. This results in a wide range of challenges faced by a CLSC. The CLSC pro-cess challenges present themselves as unbalanced demand for reuse products and supply for returning end-of-use cores. As a result, this study’s purpose was to identify the most critical challenges contributing to an unbalanced demand and supply. Also, the study aimed to pro-vide improvement proposals to improve the situation at the case company. To realise this purpose, the study followed the format of a qualitative case study with a maritime company Wärtsilä as the case company. The research data was collected using open interviews with eight key stakeholders involved in the case company’s CLSC. Data from the interviews was then transcribed and analysed with a thematic analysis method; categorising found challeng-es into challenge categories identified from the existing literature. To examine the most criti-cal CLSC challenges, the study performed a criticality analysis using Process Failure Mode & Effect Analysis (PFMEA). PFMEA assigned severity to each found challenge while also evaluat-ing the case company’s current methods for prevention and detection. The analysis resulted in 14 different challenge categories expected to contribute to unbalanced demand and sup-ply. Two new challenge categories, challenges with process knowledge and challenges with a missing seeding strategy, were added to the body of knowledge. Regarding criticality, seven challenge categories were found as critical. Critical challenges in reverse supply chain pro-cesses related to limited internal and external process knowledge and visibility of returning cores. Critical challenges in circular manufacturing processes related to low core availability, pull-ordering system, outdated inventory management practices, and a missing seeding strategy. Finally, the study proposed improvement proposals for the critical challenges that would result in more balanced demand and supply. These findings stress the individual needs of each CLSC system to perform in an optimal manner. The case company’s single source for cores created new challenges that were yet to be identified by the existing litera-ture. Also, the separation of critical challenges aids managers in focusing on the most critical ones in often problem-rich CLSCs

Contextualisation of closed-loop supply chains for sustainable development in the Chinese metal iIndustry

There are many factors influencing the sustainability of Closed-Loop Supply Chain (CLSC), in terms of industrial operation flows and environmental perspectives. This research aims to identify these factors in order to provide a better understanding of the process flows and interactions between the primary and secondary metal manufacturers and remanufacturers. In particular, it focuses on the influences of the Customer, Environment and Technology (CET) factors, with the intention of finding out “the specific approaches and techniques the Chinese metal manufacturers and remanufacturers adopt for sustainable development of the CLSC”. Qualitative case studies were performed in seven companies in the Pearl River Delta (PRD) region of South China. These companies are Small and Medium Enterprises (SMEs) of primary metal manufacturers, secondary metal remanufacturers, dismantlers, and third party reverse logistics providers. Data and information were collected through semi-structured interviews and observations on sites, in order to analyse the process flows in the supply chains. The key findings include the demonstration of the CLSC networks in the context of the Chinese metal industry, and the development of the process maps and Positioning Tool for case companies to identify themselves in the CLSC. These are theoretical and practical supports for academics and companies to understand the handling of various qualities and quantities of primary and secondary metals. Simultaneously, they assist companies in identifying and positioning themselves in the CLSC in order to define their direction for sustainable development in the long-term

Remanufacturing and product design: designing for the 7th generation

The following is taken directly from the research report. This report investigates Design for Remanufacture in terms of both detailed product design and the business context in which Design for Remanufacture may operate. Key Study Objectives • To understand the link between design and remanufacture • To understand how Design for Remanufacture can lead to increased innovation and Sustainable Development (SD) • To identify proactive strategies to further Design for Remanufactur

Forecasting of Core Returns for Remanufacture: A Time Series Analysis

Over centuries, consumption of natural resources has been on a steady increase in re-sponse to the increasing global population. Increased and unsustainable use of natural re-sources in addition to increased manufacturing is a ecting the environment adversely. Hence, governments and environmental protection agencies are implementing rm regulations for industries to reduce their footprint on environmental pollution, for instance by ensuring that their waste products are not only disposed sustainably but also reduced. In response to these regulations, industries have embraced product end-of-life management strategies. These include reverse logistic, material and product recovery, reusing, recyling and remanufacturing. This Thesis addresses one of the major challenges in remanufacturing which is uncertain-ties in the number of core returns for remanufacture. Speci cally, we propose a time series model that uses real data from a partner International OEM company that manufactures aswell as remanufactures electronic products. A unique aspect of the data that was obtained was the fact that speci c distinctions were made delineating billable return products from warranty return products for remanufacture. It is with this uniqueness that we sort to con-struct three time series model that is (a) Overall product core return; (b) Warranty return and (c) Billable return. The forecast for the overall product core return and billable return was calculated using the Seasonal ARIMA (autoregressive integrated moving average) model, whereas the war-ranty return forecast was calulated using the ARIMA model. The best model was selected on the basis of akaike information criterion. ARIMA(0,1,1)(0,1,0)[12] was selected as the best model for overall returns; ARIMA(0,1,1) was selected as the best model for warranty return and ARIMA(0,1,0)(0,1,0)[12] was selected as the best model for billable return. The se-lected models were proven to be appropriate by means of residual diagnostics which includes Box-Ljung test, residuals of ACF, ARCH e ect and Jarque Bera test. Two-thirds of the data was used to build the models. After veri cation, this models were used to forecast the remaining one-third of the data. The accuracy of these forecasting results were determined with ME, RMSE, MAE, MPE, MAPE, MASE and ACF1. Overall, though not generizable to all companies, our model proved that for our partner company the overall returns were largely driven by the billable returns hence making it a pro table venture

The impact of product returns and remanufacturing uncertainties on the dynamic performance of a multi-echelon closed-loop supply chain

We investigate a three-echelon manufacturing and remanufacturing closed-loop supply chain (CLSC) constituting of a retailer, a manufacturer and a supplier. Each echelon, apart from its usual operations in the forward SC (FSC), has its own reverse logistics (RL) operations. We assume that RL information is transparent to the FSC, and the same replenishment policies are used throughout the supply chain. We focus on the impact on dynamic performance of uncertainties in the return yield, RL lead time and the product consumption lead time. Two outcomes are studied: order rate and serviceable inventory. The results suggest that higher return yield improves dynamic performance in terms of overshoot and risk of stock-out with a unit step response as input. However, when the return yield reaches a certain level, the classic bullwhip propagation normally associated with the FSC does not always hold. The longer remanufacturing and product consumption lead times result in a higher overshoot and a longer time to recover inventory, as well as more oscillation in the step response at the upstream echelons. We also study bullwhip and inventory variance when demand is a random variable. Our analysis suggests that higher return yield contributes to reduced bullwhip and inventory variance at the echelon level but for the CLSC as a whole the level of bullwhip may decrease as well as increase as it propagates along the supply chain. The reason for such behaviour is due to the interaction of the various model parameters and should be the subject of further analytical research. Furthermore, by studying the three-echelon CLSC, we produce a general equation for eliminating inventory offsets in an n-echelon CLSC. This is helpful to managers who wish to maintain inventory service levels in multi-echelon CLSCs