The overall aim of this study is to explore the nature of Industrial Additive Manufacturing Systems as implemented by commercial practitioners, with a specific focus on flexibility within the system and wider supply chain. This study is conducted from an Operations Management perspective to identify management implications arising from the application of contemporary Industrial Additive Manufacturing in the fulfilment of demand. The generation of the theoretical constructs and their evaluation is achieved through an abductive approach. The concept of an Industrial Additive Manufacturing System is developed, through which activities, enabling mechanisms, and control architectures are demonstrated. This is complimented by the proposal of a typology of flexibilities both for the manufacturing system and its supply chain. Twelve case studies are examined through practitioner interviews, observation, and mapping of the production processes at three Industrial Additive Manufacturing companies. These explorations are complimented by interviews with customers downstream of the Additive Manufacturer, and with interviews and a survey of principal upstream machine and material suppliers. This study identifies and classifies types of flexibility relevant to Industrial Additive Manufacturing Systems. It is shown that to achieve requisite flexibilities, it is necessary to manage the whole manufacturing system, not just individual machines. By extension, the internal manufacturing systems’ ability to achieve flexibility is shown to be both facilitated and constrained by the environment in which it operates. In particular, inadequacies in the supply of materials are shown to result in suboptimal practices within the manufacturing system. The principal contribution of this thesis is therefore the development of Industrial Additive Manufacturing from a manufacturing systems perspective, and an evaluation of its implications for flexibility.