This chapter presents a comprehensive review of key dynamics in manufacturing outsourcing research, focusing on the relationship between an original equipment manufacturer (OEM) and a contract manufacturer (CM). The cooperation and coopetition relationships, along with modeling frameworks for various supply chain scenarios, are discussed. We provide a seven-step analytical framework including echelons of the supply chain, players involved, outsourcing decisions, and decision sequences for outsourcing decision analysis. Demonstrations of deriving the optimal outsourcing strategies (in-house, turnkey, or consignment) are provided, identifying conditions for win-win or win-win-win outcomes. Furthermore, we include three dynamic variations, including multi-vendor and multi-client outsourcing, private information, and product differentiation, to enrich outsourcing implications. Each variation is supported by relevant articles summarizing major focuses and modeling frameworks. The chapter concludes with a general discussion of outsourcing relationships and highlights potential research areas that arise from new challenges in the changing business environments.