| 1. |
- Lindkvist Haziri, Louise, 1982-
(författare)
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Improving Design for Remanufacturing Though Feedback from Remanufacturing to Design
- 2020
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The high demand for products in our society makes manufacturing, and the treatment of products throughout the product life cycle, crucial as it adds to the total environmental impact of a product. Initiatives such as the circular economy promote economic growth while not increasing environmental impacts. The circular economy can also be viewed as a system where the use, maintenance, reuse, remanufacturing, and recycling of materials are optimised to capture the embedded value of products. This doctoral thesis focuses on remanufacturing in particular as an environmentally preferred way to treat products that have reached their end of use. Remanufacturing is an industrial process whereby a used product is restored to its next full life cycle, and thus energy and materials can be saved compared to new production.A product that is intended for remanufacturing ought to have certain qualities such as ease of cleaning, ease of separation, and ease of reassembly in order to achieve efficient product remanufacturing. By applying design for remanufacturing (DfRem), costs can be saved as the remanufacturing operation time is reduced. Further, integrating DfRem in the design process is essential in order to achieve a more efficient and effective remanufacturing process. However, the current status in industry is that DfRem is not widely applied, and thus, products are not designed to facilitate remanufacturing. Since DfRem requires knowledge about remanufacturing, feedback from remanufacturing to design is needed for making the correct design considerations. The aim of this doctoral thesis is to expand current knowledge on feedback from remanufacturing to design and how it can be used to improve DfRem.Hence, in order to meet the aim of this thesis, both literature studies and multiple case studies were conducted. The case studies include three companies that design, manufacture, and remanufacture their products. The data collection within the case studies was predominantly conducted through semistructured interviews. The results from the case studies have been further explored in a cross-case analysis.The literature studies show the potential feedback from remanufacturing to design can be divided into three main categories: from the remanufacturing personnel, related to the process of remanufacturing, or related to the core to be remanufactured. Further, potential feedback at the case companies was found. However, currently, the potential feedback remains unsought for at the case companies. Indeed, there are barriers for feedback from remanufacturing to design, such as lack of knowledge, lack of incentives, and organisational barriers. However, there are also enablers, such as business opportunities to be gained, increased customer willingness, and laws, regulations, and standards encouraging more sustainable products.In this doctoral thesis, a framework for improving implementation of DfRem is presented, as the use of DfRem and feedback from remanufacturing to design was found to be scarce in the case companies. The developed Remanufacturing Information Feedback Framework (RIFF) focuses on breaching the barriers for feedback from remanufacturing to design. Further, the application of the RIFF promotes the implementation of DfRem methods and tools, which, when applied, could make remanufacturing more efficient and effective. Consequently, the increased application of DfRem will contribute to the overall growth of the remanufacturing market, which will also reduce the negative environmental impact and promote, in turn a more circular economy.
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| 2. |
- Kurilova-Pališaitienė, Jelena, 1985-
(författare)
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Toward Lean Remanufacturing : Challenges and Improvements in Material and Information Flows
- 2015
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Remanufacturing is an environmentally sound material recovery option which is essential to compete for sustainable manufacturing. The aim with remanufacturing at a majority of companies is to prolong physical product performance by delivering the same or betterthan-original product quality. In general, remanufacturing is an industrial process that brings used products back to useful life by requiring less effort than is demanded by the initial production process. Consequently, from a product life-cycle perspective, remanufacturing generates great product value.Remanufacturers lag behind manufacturers since they often face complex and unpredictable material and information flows. Based on a review of remanufacturing research, remanufacturing challenges in material and information flows can be classified into three groups: insufficient product quality, long and unstable process lead times, and an unpredictable level of inventory. While some remanufacturing researchers state that manufacturing and remanufacturing are significantly different, they have more in common than many other processes operations. Therefore, to sustain competitive remanufacturing, companies investigate an opportunity for improvement through the employment of lean production that generates significant benefits for manufacturers.In order to investigate the potential to address remanufacturing challenges by lean production, a Minimum time for material and information flow analysis (MiniMifa) method was developed. This method originates from the value stream mapping (VSM) method, broadly practiced to bring lean to manufacturing companies. The focus of MiniMifa was to collect empirical data on the identified groups of remanufacturing challenges from the remanufacturing perspective, and to provide a basis for the development of improvements originating from lean principles.Lean production was selected for this research due to its system perspective on material and information flows. Among the defined lean principles in remanufacturing, a pull principle was investigated at the case companies. The suggested principle demonstrated a reduction in lead time, followed by improvements in inventory level and product quality. However, in order to become lean, remanufacturers have to overcome three levels of lean remanufacturing challenges: external and internal challenges as well as lean wastes.Finally, this research reduces the gap between academia and industry by contributing with a possible solution to the identified remanufacturing challenges in material and information flows.
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| 3. |
- Wei, Shuoguo, 1986-
(författare)
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Core Acquisition Management in Remanufacturing : Current Status and Modeling Techniques
- 2015
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Remanufacturing is an important product recovery option that benefits our sustainable development. Cores, i.e. the used products/parts, are essential resources for remanufacturing. Without cores, there will not be any remanufactured products. Challenges in the core acquisition process are mainly caused by the uncertainties of: return volume, timing and core quality. Core Acquisition Management actively attempts to reduce these uncertainties and achieve a better balance of demand and return for the remanufacturers. The aim of this dissertation is to extend the knowledge of Core Acquisition Management in remanufacturing, by investigating the current status of research and industrial practice, and developing quantitative models that assist the decision making in the core acquisition process.In the dissertation, a literature review is firstly conducted to provide an overview about the current research in Core Acquisition Management. Possible further research interests, for example, more studies based on non-hybrid remanufacturing systems and imperfect substitution assumption are suggested. Through an industrial survey carried out in a fast developing remanufacturing market - China, environmental responsibility and ethical concerns, customer orientation and strategic advantage are identified as the most important motives for the remanufacturers, while customer recognition is their most serious barrier at present. Suggestions for further improving the Chinese remanufacturing industry from the policy-makers’ perspective are provided. After the above investigation, mathematical models are then developed to assist the acquisition decisions in two aspects: to deal with the uncertainties of return volume and timing, and to deal with the uncertainties of core quality.Acquisition decision about volume and timing is firstly studied from a product life cycle perspective, where the demands for remanufactured products and the core availability change over time. According to industrial observations, the remanufacturing cost decreases with respect to its core inventory. Using optimal control theory, core acquisition and remanufacturing decisions are derived to maximize the remanufacturer's profit. It is found that besides a simple bang-bang type control policy (either collecting as much as possible, or nothing), a special form of synchronizing policy (adjusting the core collection rate with demand rate) also exists. Furthermore, the acquisition decision depends greatly on the valuation of cores, and Real Option Valuation approaches are later used to capture the value of flexibility provided by owning cores when different aspects of remanufacturing environment are random. More specifically, the value of disposing a core earlier is investigated when the price of remanufactured product is uncertain, and the impact of the correlation between stochastic demand and return is also studied.To deal with the uncertainties of core quality, refund policies with different numbers of quality classes are studied. Under the assumption of uniformly distributed quality, analytical solutions for these refund policies are derived. Numerical examples indicate that the customers’ valuation of cores is an important factor influencing the return rates and the remanufacturer’s profit. Refund policies with a small number of quality classes could already bring major advantages. Credit refund policies (without deposits) are included for comparisons. In addition, within a game theory framework, the trade-off of two types of errors of the quality inspection in a deposit-refund policy is studied. The salvage values of different cores show great influences on the remanufacturer’s policy choices. The value of information transparency about the inspection errors are studied under different conditions. Interestingly, the customer may actually return more low quality cores when the inspection accuracy is improved.
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| 4. |
- Kurdve, Martin, 1971-
(författare)
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Development of collaborative green lean production systems
- 2014
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis deals with development of lean and green production systems from an action research point of view. The studies focus on Swedish-based automotive and vehicle industries and their aims to integrate sustainable thinking and environmental care into their operations management.Starting from operations management in manufacturing and corporate sustainable development, the research is built on how to integrate these two views into one production system. The systematic structure of a multiple-target improvement process with methodologies and tools designed to achieve the sustainability vision has been studied. Since lean as well as green production is based on the entire value chain, the research has gone beyond legal company limits and included the collaborative efforts between suppliers and customers in the value chain.The thesis includes six papers and describes approaches on how to implement integration, how to structure and integrate improvement management systems, how to set up an integrated monitoring and control system for the business and how to organise and redesign green lean tools and methodologies to support collaboration towards common targets.The results can be used for exploration and hypothesis formulation for further studies and development of integrated production systems and collaboration systems. The thesis helps answering how to integrate and implement company-specific green lean production systems.
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| 5. |
- Kurilova-Palisaitiene, Jelena, 1985-
(författare)
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Lean Remanufacturing : Reducing Process Lead Time
- 2018
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Remanufacturing is a product recovery option in which used products are brought back into useful life. While the remanufacturing industry stretches from heavy machinery to automotive parts, furniture, and IT sectors, it faces challenges. A majority of these challenges originate from the remanufacturing characteristics of having little control over the core (the used product or its part), high product variation, low product volumes, and a high proportion of manual work, when compared to manufacturing. Some remanufacturing challenges appear to be process challenges that prolong process lead time, making remanufacturing process inefficient.Lean is an improvement strategy with roots in the manufacturing industry. Lean helps to increase customer satisfaction, reduce costs, and improve company’s performance in delivery, quality, inventory, morale, safety, and other areas. Lean encompasses principles, tools and practices to deal with e.g. inefficient processes and long process lead times. Therefore, in this thesis lean has been selected as an improvement strategy to deal with long remanufacturing process lead times.The objective of this thesis is to expand knowledge on how lean can reduce remanufacturing process lead time. This objective is approached through literature studies and a case study conducted at four remanufacturing companies. There are five challenges that contribute to long process lead time: unpredictable core quality, quantity, and timing; weak collaboration, information exchange, and miscommunication; high inventory levels; unknown number of required operations in process and process sequence; and insufficient employee skills for process and product upgrade. When analysing the case companies’ process lead times it was found that there is a need to reduce waiting times, which account for 95 to 99 per cent of process lead times at three of the four companies.To improve remanufacturing process efficiency and reduce remanufacturing process lead time six lean practices are suggested: product families; kanban; layout for continuous flow; cross functional teams; standard operating procedures; and supplier partnerships. The suggested lean practices have a key focus on reducing waiting time since it prolongs the process lead time. This thesis contributes to lean remanufacturing research with the case study findings on lean practices to reduce remanufacturing process lead time and increase process efficiency.
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| 6. |
- Nansubuga, Brenda, 1989-
(författare)
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Ownership or Access? : A study of mobility services in the access economy
- 2023
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The access economy is a business model emphasizing temporary access and usage over permanent ownership, centered on the renting of products among individuals or organizations. Endorsed by the media, analysts, and researchers, access-based services, which allow customers to pay for the temporary use of a product without owning it, have gained popularity in various consumer and business-to-business industries, including mobility, fashion, and mechanical equipment. However, many providers of such services face difficulties attracting and retaining customers, scaling their businesses, and achieving profitability. Against this backdrop, the objectives of this research are, first, to understand how service providers in the access economy can create value for their customers to promote higher customer adoption and sustained retention rates, and second, to understand how collaboration within an ecosystem can facilitate value creation in the access economy. The thesis draws on consumer and business marketing literature to examine ownership and access dynamics. It uses the mobility service sector as a context to analyze the access economy. Four different types of access-based mobility are analyzed: carsharing, car subscriptions, e-scooter rental, and Mobility-as-a-Service (MaaS). The papers appended to the thesis use different methods, including a systematic review, two case studies, a survey, and a conceptual study to address the research purpose. The analysis is conducted from three different perspectives: customer, service provider, and ecosystem, to provide a more comprehensive understanding of value creation in the access economy. The thesis contributes to the literature on the access economy by identifying various business models within access-based mobility and emphasizing the role of collaboration among ecosystem actors. Furthermore, it provides practical implications for service providers to improve their offerings and attract more customers.
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| 7. |
- Vogt Duberg, Johan, 1995-
(författare)
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Remanufacturing Initiation for Original Equipment Manufacturers
- 2024
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Remanufacturing is an industrial process in which a core – a used, discarded, or broken product – is transformed into a product with a like-new specification and condition. However, to this date, remanufacturing activities on the market are few compared to manufacturing. There are several types of remanufacturers; the least common type is the original equipment remanufacturer, an original equipment manufacturer that not only manufactures new products but also remanufactures cores of its own products. Remanufacturing is potentially becoming a more widely used industrial process for original equipment manufacturers, and increased remanufacturing activities can positively contribute to the environment. The contribution comes from a reduction of raw material and energy consumption compared to manufacturing. Therefore, remanufacturing has the potential to decouple environmental impact from economic growth, thus contributing to more sustainable societies. However, assessing the benefits of remanufacturing does not directly correlate to growth within the remanufacturing industry. To encapsulate the environmental, social, and economic benefits of remanufacturing, manufacturers need to be aware of how remanufacturing can be initiated and implemented in practice. Therefore, the objective of this dissertation is to develop support measures for original equipment manufacturers to initiate profitable remanufacturing.This research takes a stand in case study and transdisciplinary research where the initiation of profitable remanufacturing is studied at two original equipment manufacturers. The research study developed knowledge of how remanufacturing could be incorporated into existing operations at original equipment manufacturers. In parallel, financial assessments based on cost-benefit analysis were built to measure how well the case companies could perform remanufacturing. For the case study research, seven remanufacturing scenarios were developed, ranging from centralised remanufacturing performed by the original equipment manufacturer to decentralised performed at multiple locations using a retail network. Which scenario is preferable depends on, for example, risk-consciousness, cooperation between actors, and volume targets. However, given ideal circumstances, remanufacturing in-house in a centralised scenario was shown to be the most beneficial for the investigated original equipment manufacturer since the fewer middle hands and economies of scale also potentially enable lower costs.For the transdisciplinary research, the remanufacturing initiation was business model-centric, meaning that the remanufacturing system was a consequence of a decision for a specific business model. Here, a scenario-based analysis was developed to understand under which circumstances the business model with remanufacturing was more lucrative for the provider – the original equipment manufacturer – and less costly for the users – the customers. For this, a systematic assessment approach was developed consisting of three steps: (1) provide a cost overview for each business model, (2) create scenarios by modifying the cost drivers, and (3) combine scenarios to reach synergetic effects.Based on the case study, two sets of four prerequisites for initiating remanufacturing were derived. These are divided into essential and supporting prerequisites and illustrated through a framework called the Remanufacturing Rocket. The essential prerequisites highlight fundamental requirements to perform remanufacturing. Should one of these four factors be missing, remanufacturing cannot be successfully initiated. The supporting prerequisites are valuable to enhance the effectiveness and efficiency of the process, such as through streamlined operations, organisational change, or information exchange. Hence, to reach the fullest potential of remanufacturing, both the essential and the supporting prerequisites are needed.Furthermore, the area of financial assessments was explored in a systematic literature review to identify insights for developing such assessments tailored for individual original equipment manufacturers in initiating remanufacturing. For this, six perspectives for framing financial assessments are proposed. These cover the system boundaries for the assessments as well as the individual needs and visions of original equipment manufacturers. Additionally, a framework was developed to select financial assessment models for remanufacturing initiations based on ease of use and capability to handle complex datasets.Conclusively, it is proposed to apply the prerequisites for initiating remanufacturing together with a financial assessment in an iterative manner to investigate the profitability for original equipment manufacturers to initiate remanufacturing. The essential prerequisites influence the first iteration of the financial assessment, which then contributes to refinements of how the essential prerequisites should be aligned in an economically preferable way. Once satisfactory, another iterative process could be initiated between the supporting prerequisites and the financial assessment. By using the proposed approach, the prospects of profitable remanufacturing could be thoroughly investigated before attempting to initiate a process in practice, thus reducing the number of resources spent in vain. Additionally, the iterative process was integrated into a 5-step Approach For Initiating Remanufacturing (5AFIR) to guide original equipment manufacturers towards initiating profitable remanufacturing.
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| 8. |
- Wasserbaur, Raphael, 1989-
(författare)
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Simulation Modelling of a Shift to Service-Based Offerings : Resource efficiency and operational implications in the context of the circular economy
- 2020
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The unsustainable levels of resource use and emissions of our economies and their threat to future generations are core issues of our time. The circular economy (CE) conceptualises a different type of economy that is restorative and regenerative by design and aims to keep products, components and materials at their highest utility and value at all times, distinguishing between technical and biological cycles.The novelty of the CE requires the development of new analytical tools and methods as well as ways of thinking to understand its consequences. This research summarises four years of research on the topic of systems analysis and simulation modelling in the domain of the CE. Three topics were of major interest: First, what are the resource efficiency implications of a shift toward a CE? Second, what are the operational implications of a shift to a CE? And finally, how can systemic changes towards a CE be understood and planned? Four studies were conducted addressing the three research questions. The first study applies material flow analysis to a washing machine manufacturer case and looks at how different business models affect the resource flows of critical resources. It finds that service-based offerings lead to higher overall resource efficiency. The second study focuses on the implications of CE initiatives on the maintenance activities of a heat-as-a-service provider. It shows that the shift to service-based offerings requires service providers to face worse-before-better situations where long-term benefits offset short-term disadvantages. The third study is a simulation-based case study of laundry practices in Sweden. It compares a sharing economy scenario where a population shares washing machines with a scenario where the majority of people own the washing machines they are using. The results indicate that in Sweden and Europe in general, sharing has significant resource savings potential in the domestic laundry sector. The fourth study is a conceptualisation of design fixation to higher levels of analysis. It identifies examples of fixations on the organisational and institutional level. In addition, it argues that in order to design sustainable sociotechnical systems, aspects like governmental policies and business models need to be considered design parameters.A shift to a CE needs to happen on many levels of society. This research presents simulation models that can support corporate and political decision makers in the shift to a CE. It shows that in order to understand the CE, the analysis has to be, on the one hand, able to simulate system dynamics, and on the other hand connect the multiple levels of society.
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| 9. |
- Lindkvist, Louise
(författare)
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Exploring Product Life-Cycle Information Flows with a Focus on Remanufacturing
- 2014
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Our daily lives and welfare rely heavily on products. Considering that climate change is caused by humans, it is important to handle and use products in a sustainable manner; remanufacturing is one such way to accomplish this. Remanufacturing is an industrial process where products are restored into useful life. However, few products are designed for remanufacturing, which sometimes makes remanufacturing impossible or difficult to perform. Traditionally, the design focus has been on the manufacturing and use phases. The product life-cycle perspective, however, is required to obtain a more sustainable product life-cycle.As the remanufacturing process is characterised by process steps such as inspection, disassembly, cleaning and reprocessing, the often labour-intensive remanufacturing process has specific requirements on the design. Further, the remanufacturing process is characterised by uncertainties such as when used products are expected and what state they will be in when they arrive. Information from the product life-cycle such as drawings and service reports could potentially facilitate the remanufacturing process. Further, feedback from remanufacturing to product design could improve the design of the next generation of products.The objective of this thesis is to identify and analyse product life-cycle information flows with a particular focus on remanufacturing.The design research methodology framework has been used to outline, plan and support the research. Previous research in the area has been assessed through a literature study, while the case study methodology was applied for carrying out the empirical studies. The data collection methods used in the case studies were semi-structured interviews, workshops and document analysis.The result from the literature study shows that feedback such as suggestions for improvement from remanufacturing personnel, process data, and data about wear on components could help to improve the design of the next generation of products. Further, design changes could lead to a more efficient remanufacturing process. The three industrial cases presented in this licentiate thesis fail to explore the full potential of remanufacturing feedback to product design. All in all, remanufacturing is sufficiently included in the information flows of the product life-cycle. Design for remanufacturing is not applied in any of the industrial cases studied.
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