| Global sourcing benefits assembly systems from the perspective of both cost and technology; however, increasingly frequent supply risks hinder the utilization of those advantages. This dissertation mainly studies components’procurement decisions for assembly systems under global sourcing. First, some feasible mitigation measures for supply risks are systematically proposed from an operational perspective. Then, this dissertation quantificationally investigates three component procurement problems under different operational environments by mathematical modeling. Under the objective of cost reduction and profit improvement and through using the theoretical derivation methods of mathematical analysis, operations research, optimization method, and game theory and jointly using numerical experiments, these researches analyze optimal component procurement decisions under supply risks and explore the feasibility and effectiveness of various risk mitigation measures.Firstly, based on the previous literature and the enterprise operational practice, this dissertation concludes operational characteristics of assembly systems in China. Then, three common supply risks that are faced by assembly systems when carrying out global sourcing strategy are analyzed, i.e., uncertain procurement lead-time, supply disruption, and uncertain yield. Furthermore, some risk mitigation measures from the operational level are proposed.Secondly, this dissertation studies how assembly systems should use a capacitated expediting service to achieve the collaborative procurement between overseas and local components when the transportation time of the overseas sourcing is uncertain. The research finds optimal expediting timing for overseas sourcing and optimal arriving time for local sourcing. Then, the impacts of overseas lead-time volatility on the optimal decisions are explored. In addition, this research discusses two decision problems that are relevant to the implementation of the expediting service, i.e., safety lead-time and expediting capacity investment. The research reveals the value of the expediting on promoting the coordination of the sourcing from overseas and the sourcing from home country. In addition, the results provide several managerial insights for the assembly systems to take full advantage of expediting.Thirdly, this dissertation considers an assemble-to-order (ATO) system’s component procurement problem when overseas suppliers have disruption risks. The assembler can rely on local components’ responsive supply to mitigate the disruption risk. The local components can be purchased before and after the possible disruption events are realized. This work derives optimal component sourcing decisions. Based on the optimal decisions, the research studies how the assembler should balance between the low-cost supply from overseas and the responsive supply from home country and explores the value of the flexible local sourcing strategy on risk mitigating and the ATO system’s performance. In addition, the research proposes a heuristic policy for firms to carry out in reality more simply, and the numerical experiment results show that this policy approximates the optimal sourcing policy well.Finally, the dissertation discusses how assembly systems should utilize the local spot market to mitigate the risk of uncertain yield from overseas sourcing. After finishing the overseas sourcing, the assembler can replenish the shortage components from the spot market. The research derives optimal component procurement and replenishment decisions and explores the role of the spot market on mitigating the risk of uncertain yield. Furthermore, the research studies the impacts of the cooperation arrangement between the assembler and the downstream distributor and the varying of some market conditions on the role of spot market.
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