Browsing by Subject "Supply chain"

This dissertation is written in three progressively restrictive parts. Part I is a set of two expansive essays on collaborative supply chain management that proposes several new perspectives and interconnections between current day global business and economic issues, and the evolving supply chain structures and decision-making paradigms that depend on extensive inter-firm collaboration. Part I also develops new guidelines for both practitioners as well as academic researchers in their quest to incorporate collaborative requirements as an explicit component of existing planning frameworks and modeling approaches. Part I further comments on how the technological evolution of manufacturing, service, and general business processes have led to decentralized structures that require a fundamentally collaborative approach to the planning of such processes. We also argue that existing supply chain decision-making and planning approaches are modeled in the fashion of corporate and enterprise resource planning systems, which given their scope, limit the extent of collaboration in both planning and in execution. The arguments and discussion in this part are not specific to any particular supply chain function and is without technological bias. The frameworks presented in Part I are also unified in their approach to managing supply chains of service providers, manufacturing partners, or some combination of both types of activities. This unified presentation is also a fundamental contribution of this first part of the dissertation.

Part II of the dissertation, while still expansive in scope of application and the range of industry sectors and supply chain environments discussed, develops the ideas presented in Part I for more specific (or functional) categories of business processes. A commonly accepted categorization of operational processes, at least in manufacturing settings, is into (i) product design and development or related projects, which are akin to services in the nature and interaction between implied tasks, (ii) procurement, production, and customer service processes, and (iii) logistics and distribution networks. Projects are typically represented as a network of inter-related activities bound by a common purpose, and by a time-line dictated by a finite product or project life cycle; activities are also sometimes defined and created in response to project environments. Processes in the procurement, production, customer service, or logistics domains, on the other hand, are typically modeled as a set of inter-related but more loosely coupled activities that are repeated indefinitely across multiple product or project life cycles. Our primary concern in Part II is to understand environments where projects and processes span multiple firms, and therefore require a collaborative effort, not only for executing the activities entailed, but also in the planning of the tasks and projects.

Modeling of supply chain management problems (such as those discussed subsequently in Part III) assume that the fundamental structure of tasks and processes are at least well-defined for analysis and subsequent design of parameters for optimal performance. Often, however, the inclusion and structuring of these tasks is also a collaborative exercise that requires negotiation and careful consideration of the costs and advantages presented by alternative sets of tasks. The scope of tasks is also frequently determined by their assignment to one or more firms with differing capabilities. For example, the range of logistics activities and services provided by a specialized firm would be greater than a manufacturer assuming additional responsibility for the distribution or procurement logistics. Similarly, the capabilities of a supplier would either expand or restrict the range of tasks that would be included in the design and development of a product or a service. Therefore, Part II of the dissertation, consisting of Chapters 4 and 5, develops strategic frameworks that can allow the definition and structuring of tasks and processes in a collaborative setting. These chapters present frameworks for strategy and for defining project or process objectives which are commonly the guideposts for task definition and structuring.

These frameworks presented in Part II can also help determine the degree of collaboration either warranted or indeed suitable for different project and logistics environments. Thus, we propose that some business and technology environments call for more cohesive or coupled structuring of tasks that in turn require collaborative frameworks for planning and execution. Some other environments, either as a result of market forces or technological constraints, are a bad fit for collaborative efforts unless they are seamless and frictionless. Identifying such environments through a small set of market and technological factors is a fundamental contribution of Part II of the dissertation. Similar to our efforts in Part I, we also chart the evolution of collaborative planning and execution environments; here we adopt a more direct case based approach to illustrating issues, and related concepts. Another significant contribution of this second part is to outline how various facets of the operating environment shape the parameters of the collaborative arrangements between partner firms. In particular, we address the environmental and strategic forces that motivate a model of work sharing in environments where collaboration is not a technological requirement. Thus, we address the fundamental value proposition in collaborative logistics management for the outsourcing provider and the contracting firm, and discuss how product or process technology and structure influences such choices by firms.

Part III, which is more restrictive in its statements and conclusions, is devoted to models of collaborative supply chain management that are motivated by the imperatives outlined in Part I, but whose elements are defined by the strategic frameworks and structuring guidelines of Part II . While Part III derives guidance from Part II in the formulation of its models, it can also be viewed and read independently for its contributions to the (related) academic literature. Part III consists again of two independent modeling exercises. Through either of these exercises, we address two of the most important problems in collaborative supply chain planning: partner selection, or alternatively task and project assignment, and decentralized capacity management in a supply chain or logistics environment. These models describe two environments where collaborative planning is vital to the success of firms: (i decentralized and collaborative projects or programs that frequently determine how supply chains of diverse firms are structured and take form, and (ii) decentralized logistics and transportation systems where firms in a supply chain must invest in common infrastructure, and further determine the material flows utilizing such infrastructure. In both cases, we show how decentralized structures can be inefficient relative to centralized decision-models, while characterizing the equilibrium behavior of firms in decentralized decision-frameworks under the proportional risk-sharing regimes. We then provide mechanisms that can coordinate the decentralized systems. These mechanisms turn out to be highly conditional on the rules of information exchange and the decision-hierarchies in the supply chain, and therefore can claim to remedy coordination problems in only a subset of collaborative environments. However, this subset -- as it turns out -- is not insignificant, as many different supply chains operate with such restrictive information exchange and decision-hierarchies.

In the next introductory chapter, we provide a more detailed synopsis of Parts I-III with the objective of identifying the considerable interconnections between the various chapters within the three parts. We also aim to highlight the contributions of the work to various streams of academic literature. Throughout this dissertation, we strive to maintain a dual tone of discussion: One for practitioners and researchers in the field of operations strategy that focuses on synthesizing insights on supply chain structure and the crucial elements of collaborative supply chain planning for the sake of managers, and the second theme focusing on more fundamental operations research problems underlying the collaborative planning environment.

More companies are beginning to manage the environmental impacts of their supply chain in addition to their own operations. Supply chain pressure has been shown to be generally effective at increasing practices with lower environmental practices (sustainable practices) in suppliers. However, questions have been raised about exactly how small and medium-sized enterprises (SMEs) in supply chains respond to pressure from business customers for sustainable practices and what factors influence their response. This study develops a framework for understanding what factors influence how SMEs respond to a variety of drivers of sustainability, which is then adapted to guide an empirical study of how SMEs respond to supply chain pressure for sustainable practices. A survey of 100 companies across North Carolina found suppliers generally comply with or exceed requirements from business customers. The role of supply chain pressure in suppliers' decisions to exceed requirements needs further research. The study also found evidence that supply chain pressure can act as a ceiling on what practices companies adopt by causing suppliers to abandon practices that exceeded customer requirements and were not recognized or rewarded. Care needs to be taken in designing supply chain management strategies to avoid supply chain pressure being counterproductive at increasing proactive SME sustainability.