Dissertations / Theses on the topic 'Critical materials supply chains'

The United States economic and national security sectors remain vulnerable to shortages of critical materials due to the risks posed by disruptions in globally-dispersed supply networks. Numerous methods over the past 10 years have been proposed to identify, assess, and evaluate risks in critical material supply chains. This praxis provides a method to quantify the impact of supply disruptions and inform the application of risk mitigation measures for a critical material supply chain from mineral deposits to final platform. It proposes a Bayesian network modeling method not yet applied to the problem in publicly available studies and fits with an assessment methodology proposed by the National Science and Technology Center (NSTC). Results from this study provide indicative answers to how supply disruptions propagate through a selected critical material supply network, which nodes are vulnerable to supply disruptions, and whether mitigating actions can reduce the impact of supply disruptions. The approach here demonstrates that a Bayesian network model can be one of the tools in a criticality assessment methodology.

Thesis (S.M.)--Massachusetts Institute of Technology, Sloan School of Management; and, (S.M.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering; in conjunction with the Leaders for Manufacturing Program, Massachusetts Institute of Technology, 2000.
Also available online at the MIT Theses Online homepage .
Includes bibliographical references (p. 80).
The industrial gas turbine (IGT) market is experiencing exponential growth where competition is based upon technical performance and time to market. Product sales are limited by the ability of the Original Equipment Manufacturer (OEM) to coordinate manufacturers and assemblers to deliver turbines to customers in a timely manner. The company's logistics and supply chain systems have evolved from a traditional low volume job-shop environment and must now cope with a marked increase in product demand. OEM's must now manage the manufacture and assembly of thousands of turbine parts across an international and complex supply chain in a robust and agile manner. This requires the effective integration of internal and external logistics, supply chain and engineering talent. Current performance has been plagued with poor sourcing reliability, low quality and exploding lead times. This has resulted in sluggish response to customer demand and loss in earnings. This thesis seeks to recommend inventory placement strategies to improve sourcing reliability while identifying root causes and recommending improvements. It will also address the importance of the time-value of material in addressing investment and materials management decisions.
by Miriam Park.
S.M.

Composites have been increasingly used in different applications in the last decade, especially in aerospace due to their high strength and lightweight characteristics. Indeed, the latest models of Airbus (A350) and Boeing (B787) have employed more than 50 wt% of composites, mainly Carbon Fibre Reinforced Polymers (CFRP). Yet, the increased use of CFRP has raised the environmental concerns about their end-of-life related to waste disposal, consumption of non-renewable resources for manufacturing and the need to recycle CFRP wastes. In this study, a generic model is developed in order to propose an optimal management of aerospace CFRP wastes taking into account economic and environmental objectives. Firstly, a life-cycle systemic approach is used to model the environmental impacts of CFRP recycling processes focusing on Global Warming Potential (GWP) following the guidelines of Life Cycle Assessment (LCA). The whole supply chain for recycling CFRP pathways is then modelled from aircraft dismantling sites to the reuse of recycled fibres in various applications. A multi-objective optimisation strategy based on mathematical programming, -constraint and lexicographic methods with appropriate decisionmaking techniques (M-TOPSIS, PROMETHEE-GAIA) has been developed to determine CFRP waste supply chain configurations. Various scenarios have been studied in order to take account the potential of existing recycling sites in a mono-period visions as well as the deployment of new sites in a multi-period approach considering the case study of France for illustration purpose. The solutions obtained from optimisation process allow developing optimal strategies for the implementation of CFRP recovery with recycled fibres (of acceptable quality) for the targeted substitution use while minimising cost /maximising profit for an economic criterion and minimising an environmental impact based on GWP.

Together with electrification of the transportation sector and the introduction of renewable energy in the electricity grid, the demand for lithium-ion batteries is increasing. As a result of this emerging need, large-scale battery manufacturing is a promising and developing industry. Currently, there exist a challenge for lithium-ion battery manufacturers to ensure supply of the desired material and to guarantee operation in a sustainable manner. The material included in a battery cell possess unique characteristics, has high criticality, and experience limited availability, which has resulted in an un- certain business environment with high complexity. Hence, the aim of this thesis is to investigate how unique material characteristics affect the purchasing environment and can be considered to obtain a sustainable inbound supply chain for lithium-ion battery manufacturers. The study is based on the following research question; How can purchasing of critical direct material for lithium-ion battery manufacturers support a sustainable inbound supply chain?

Supply chain literature has increasingly argued that supply chains are being used by a wide range of industries to generate innovations which deliver competitive advantage, and that social factors such as trust and collaboration play a key role in making effective supply chain management (SCM). Closer examination of the research suggests that much of this literature is based on studies of industries which deliver consumer products and these studies are predominantly conducted within a positivist research framework. This research bias has resulted in far less attention being paid to studies of mature industrial markets. This case study seeks to redress such bias by posing an overall question regarding the role of social factors in innovation within a well established supply chain which existed across three mature, capital intensive industries � steel manufacturing, transport and railroad track construction and working outside the positivist paradigm by using a m ultidisciplinary research approach within a �critical realist framework�. In responding to the overall research question, three subordinate questions were explored. Firstly, how well suited are present corporate governance structures of individual organisations to deal with the newly emerging interconnected organisational structures in order to support the generation of innovations within supply chains? Secondly, what has been the impact of the widespread adoption of information technology in generating innovation in supply chains? And thirdly, what is the role played by interorganisational social networks in generating innovations within supply chains? The overall findings were that the social factors played a far more important role than had hitherto been acknowledged in either supporting or inhibiting innovation within supply chains. Corporate governance was seen to generally inhibit innovation between organisations. The claims of much of the SCM literature which asserts a strong link between IT and innovation in supply chains was not supported. In fact, it was found that the majority of subjects preferred to get information through social systems. The role of interorganisational networks (IONs) was found to be most effective at generating incremental innovations aimed at maintaining operational efficiency. A critical realist research approach was able to uncover some difficulties associated with a purely positivist research paradigm which restricts investigation to the empirical level of ontology. The critical realist approach was able to explore social causal mechanisms and structures which were not as readily accessible at the empirical level of inves tigation. It was found that multiple realities existed across the supply chain, and that the positivist assumption of a mono reality which underpins much of the enterprise resource planning (ERP), process management and governance approaches was in fact inhibiting the ability of the social system to be innovative and ultimately driving up costs. In fact a process management approach supported by information technology and operating within present corporate governance structures created conflicting goals which increased complexity. A key finding of this study was how the open social system of the supply chain used dynamic relationships to overcome the rigidities and complexity of a closed systems logic embedded in the formal governance and information systems.

The medical technology sector in Germany is considered an innovative, fast-growing and promising industry, being third behind the USA and Japan as the biggest market in the world, worth 17.1 billion euros. Consequently, supply chain success is of high importance. This research identified the Critical Success Factors (CSFs) for Original Equipment Manufacturers that are involved within medical technology supply chains in Germany. This thesis begins with a full literature review on Supply Chain Management (SCM) in the medical technology sector and presents the current state of academic discussion on CSFs in this context. The literary analysis identified that most academic research focuses on developing theory based on supply chains of the manufacturing sector with the consumer market as their primary concern, with limited insights into Medical Technology Supply Chains (MTSCs). This was a main driver for the exploration of the drivers and barriers extant in this sector. Two studies were designed to address the identified research gaps. The first study was a qualitative research using multiple case studies and was divided in two phases. Phase A involved 15 German manufacturers of medical technology products and focused on identifying the CSFs in this sector. Phase B involved 14 German manufacturers and uncovered issues and weaknesses of their current SCM strategies by means of an assessment tool developed specially for this study. The second study consisted of an action research project, using interviews and participative workshops to develop an understanding on how organisations in this sector can improve operations using the CSFs concept while offering insights into the actual implementation of SCM strategies and the behavioural aspects of change management in this context. The findings extend theory and provide insights into real-world practitioner challenges and priorities. The outcomes of this study propose that the prioritised combination of the identified CSFs leads to better performance of OEMs in the German MTSC sector, which shifts our understanding of how practitioners prioritise CSFs. Furthermore, this thesis addresses the qualitative knowledge gap around the relational aspects of implementing SCM practices within this sector, while exploring relationships between stakeholders during the process of introducing these changes. These findings challenge existing generic assumptions about supply chain CSFs, as well as adding to SCM, CSF, and medical technology research and knowledge.

Dissertation (PhD)--Stellenbosch, 2004.
ENGLISH ABSTRACT: The dissertation reflects the research done on the design principles and success factors for the operation of cross dock facilities in grocery and retail supply chains. The cross dock is a particular facility in the supply chain where goods are received from suppliers, sorted without storage of the goods, and then efficiently moved to downstream customers. Cross docks are not a new operation. However, the use in high volume grocery and retail operational capabilities is poorly understood and is not uniquely defined. The problem is that cross docks are often seen as extensions of warehouses. The same personnel, systems and processes are applied and the efficiency potential of the cross dock is not achieved. Warehouses are orientated towards storing the full range of product and allowing the pick to be done from this storage buffer to provide any or all of these products to a customer. Cross docks will only handle products that are used in larger quantities and that are sent to most, if not all, the customers. The cross dock is therefore distinct and very different from the traditional warehouse. The published research tends to focus on the technical aspects of the cross dock layout. This research is primarily in the scheduling of the trucks into the yard of the facility; the allocation of trucks to specific doors of the facility; and the allocation of doors to receiving and despatch functions within the facility. Very little information or research reflects the design principles and success factors for the cross dock and its supply chain. The only classification of the cross dock in the literature is whether the barcode is added to the item before or after receipt at the cross dock. For this research work a literature survey was conducted and five major operations were reviewed, in South Africa and the USA. The research empirically drew logical conclusions, which were tested in the operations and found to be correct. This allowed the design principles and success factors to be determined for a successful cross dock. The research extends the knowledge of the cross dock operation and design: - • A new classification for the feasible types of cross docks in the supply chain was developed. Three factors are shown to be of primary importance: - o Where in the supply chain the identification of specific items for a customer is done; o Where the sort is done for the items to be delivered to a customer; and o Whether the supplier is providing one product or multiple products to the sort. From these three factors, eight potential classifications could be defined. However, only three practical types of cross dock can be determined from these eight alternatives. These are named in this research as Cross Dock Managed Load (CML); Joint Managed Load (JML); and the Supplier Managed Load (SML). The cross dock is far more effective than the warehouse when the total work (excluding inventory) is considered. The earlier in the supply chain the product is identified for the use of the entire downstream supply chain, the more effective will be the total supply chain. Thus the greatest supply chain effectiveness possible is with the SML, then the JML and finally the CML. • The operation of a cross dock is very similar to a continuous manufacturing process. There is no buffer of stock to decouple the inbound and outbound processes, and the operation takes place in a restricted area. However, in the retail chain, the workload alters with different orders and different days. Daily load differences vary by as much as 90%. This results in vastly different workloads and variations of throughput. This is similar to a batch operation with highly variable workloads between batches. The literature recommends the use of Just in Time (JIT) practice for cross docks. This is inappropriate as its primary requirements are continuous full volume operation and continuous small improvements to achieve a balanced operation. The most appropriate method of process improvement is the Theory of Constraints (TO C) and not JlT. • The management must have a detailed, disciplined approach. This implies standardised methods of operation, and a high degree of training. Equally there is the requirement for a special type of personnel to operate the cross dock. These operating personnel must be able to operate with precision (i.e. very low error rates) and be able to maintain this capability for continuous periods. • The systems required for a successful operation must include the capabilities of Yard Management, WMS for cross docking, Order Management with Advanced Shipping Notice (ASN) capability and Track and Trace across the supply chain. The items need to be identified by a barcode. The information required on the barcode will be determined by. the information systems capability of the least advanced service provider in the supply chain. If this service provider can receive and transmit all the data required for the supply chain from and to the other members, then the barcode need only be an identification number of the specific item. The data pertaining to the items is then passed from system to system in the supply chain. If data movement is not possible between all the parties in the entire supply chain, then the barcode must contain the information that will identify the item, the origin and the final delivery destination. If the items are delivered as part of a consignment, a further quantum of information is required to identify the total number of items in the consignment and the specific item within the consignment. • The research shows that the overall capability of the cross dock or its maximum capacity is the combination of the capability of the personnel and the cross dock design. Restrictions on either the personnel capability or the design of the cross dock, or both, severely reduces the effectiveness of the cross dock. • The previous research on the sequence of allocation of trucks to specific doors within the cross dock can be enhanced with a new sequencing method. The new method allocates the transport, in sequence of arrival, to the open door that either numrruses the walk distance in the facility; or maximises the completion of the consignments in order to minimise the area required to build the consignments; or a combination of both. The choice of these will be determined by the constraints imposed by the design of the building. This is an important extension as this ties the supply chain into the cross dock operation, rather than looking at the cross dock in isolation as has been done in this previous research. • The factors that influence the design of a cross dock as to its size, shape, number of doors, and the specifically required additional areas, is defined in detail. The principles of these factors and their inter-relationships and dependencies are used in a detailed design for a cross dock. The detailed design process is set out from data analysis through to the actual size calculations and layouts. Measurements of walk distance and sort movement are used to determine the most effective design. The design is shown to be considerably more effective than the older designs. This work has significantly extended the research on the design principles and success factors for implementation of cross docks in retail supply chains. The research derives a unique new classification for cross docks. An improvement is made to existing research on the allocation of the transport to particular doors in the cross dock. The operation, management and personnel are shown to require specific characteristics. The information systems required for effective cross docks is determined and defined. The identification of the individual items by barcode and the information required within the barcode depending on the information sophistication of the service providers in the supply chain is defined. A detail process to design a cross dock is evolved, with the full knowledge of the factors that must be considered and their interrelationships. Measurements to determine the effectiveness of the design are used to choose the most appropriate design. All these are then synthesised into a new design, which is far more effective than any of the other designs researched. The design process will produce a very effective cross dock as has been demonstrated with a new facility.
AFRIKAANSE OPSOMMING: geen opsomming

The use of different materials is a central part of our development, especially in the electronics industry since it is dependent on materials such as gold, silver and copper etc. to achieve the required performance. The material consumption is increasing, while material production is limited to a few countries. Industries and companies that consume unusual or large amounts of material are most exposed to this problem. Therefore it is important for companies to be able to identify their critical materials. There is a lack of systems that can identify different materials criticality at a company level. This report proposes a system that can identify critical materials at a company level, regardless of the company's industry and size. By combining a literature study with a case study in a leading electronic company, a system that identifies materials criticality at a company level was developed. The theoretical study consisted of a comparison between three existing systems for evaluating critical materials, combined with a qualitative study, interviews, that were conducted at the electronic company Ericsson. The developed system evaluates a material's criticality based on two parameters; supply risk and corporate importance. Each parameter includes several categories and indicators that measure the materials criticality. By testing the system on Ericsson's most important and used materials such as; Al, Au, Ag, Cu, etc., it was found that the company do not have any critical materials. The developed systems corporate importance part is configurable, which makes it company-specific. It is up each company to customize it for their own business and situation. The case study also showed that a nation´s critical material doesn’t necessarily need to be company critical just because the company operates within the nation, it mainly depend on the material usage. Companies that manufacture end products so called OEMs in the electronics industry don’t usually buy materials directly from the mine, but components containing these materials. This makes it difficult for OEMs to trace the material origin. Apart from the material production concentration that is limited to a few countries, the knowledge of how to manufacture certain components may also be limited, by being concentrated in few countries. This factor makes the OEMs to become more dependent on certain suppliers, which can affect the business.

In this thesis a complete portfolio model for supporting development of purchasing strategies for raw material at Casco Adhesives is developed. The model consists of a classification tool which divides the raw material into four distinct quadrants with different main tasks. The second part of the model is a strategy template which gathers necessary information dependent on the quadrant.

The increasing demand for mineral-based resources that face supply risks calls for managing the supply chains for these resources at the regional level. Cobalt is a widely used cathode material in lithium-ion batteries, which form the major portion of batteries used for renewable energy storage - a necessary technology for electrifying mobility and overcoming the challenge of intermittency, thus making renewable energy more reliable and energy generation more sustainable. This necessitates understanding cobalt's supply risks and for the Untied States, identifying sources of cobalt available for future use via recycling or mining. These needs are addressed in this work using single and multiregional input-output (MRIO) analysis in combination with graph theory. An MRIO-based approach is developed to obtain the trade network of cobalt and offer a more expedient way to identify potential critical material sources embodied in commodities made domestically. Commodities containing cobalt were disaggregated from two input-output (IO) models and the trade structure of cobalt at the national and state level was observed and compared. The significance of identified key sectors is measured according to several criteria and differences in sectors highlighted in the national versus subnational networks suggests that analysis at the two regional aggregation levels provides alternative insights. Results from mining the IO networks for cobalt highlight the geographical distribution of its use and industries to further investigate as potential sources for secondary feedstock.

No
Supply chain management (SCM) is a major issue in many industries as organisations begin to appreciate the criticality of creating an integrated relationship with their suppliers and customers, as well as all other stakeholders. Managing the supply chain has become a way of improving competitiveness by reducing uncertainty and enhancing customer service. The concept of value chain management (VCM) is becoming quite prevalent in industry. Despite this popularity, there is little evidence of the development of accompanying theory in the literature. Without theory development, it is difficult to identify specific hypotheses and propositions, which can be tested, resulting in research that lacks focus and is perhaps irrelevant. This paper analyses the merits and limitations of SCM and provides broader awareness of VCM, its critical success factors and proposes a model, which covers four key elements supported by a drive on agility and speed.

碩士
國立虎尾科技大學
工業管理系工業工程與管理碩士班
106
In recent years, due to globalization and the integration of the world’s economies, supply chains have become more complex and vulnerable. Therefore, supply chains need to be more resilient in response to such challenges. As supply chain interruptions are the cause of financial loss and reductions in revenue, it is important to develop resilience in the best possible time. However, only a few studies have attempted to improve clarity by combining the resilience of different supply chains and building it in a more integrated and effective way. This study will develop an assessment system to identify the key factors affecting the resilience capability of supply chains. First, the research develops a system that improves the resilience capability of supply chains based on the analysis of relevant literature. After that, we built an assessment approach combining Grey theory, DEMATEL (decision-making trial and evaluation laboratory), ANP (analytic network process) and ISM (interpretive structural modelling) to find the critical capability of resilience in a supply chain system. The results show that the most important factors for an electronic manufacturing supply chain system are as follows: knowledge management (post-disruption), increase in flexibility, contingency planning and agility. The results also suggest that these critical elements will support and help supply chain managers to capture and improve the effectiveness of the supply chain and efficiency in other operations.

A stochastic model for predicting the lifetime of composite laminates subjected to multiaxial fatigue loading is proposed. The model is based on the application of Markov chains to the well known "critical element" model for the fatigue of composite laminates. The model considers the accumulation of fatigue damage as an evolutionary random process characterized by changes in the global compliance of a laminate. These changes are modeled as nonstationary, discrete time, discrete state Markov processes (Markov chains) utilizing stationary Markov chains and polynomial transformations of their indexing parameters. The stationary Markov chains are developed on the assumption of "equivalent damage". Their parameters are determined from experimental data. The Markov chain models yield full cycle dependent probability distributions for the changes in laminate compliance. These changes and their respective distributions are used as input into a mechanical analysis to determine the stresses on the life controlling critical elements of a laminate. The stresses on the critical elements and their derived probability distributions are used in turn to predict the lifetime of a laminate based on Markov chain models of the fatigue behavior of the critical elements. The predictive capability of the proposed model is demonstrated by comparison with experimental results.