There is an interesting tension that exists within the HRM literature with regard to employment subsystems. On the one hand, a clear pattern is emerging in strategic HRM research that suggests that HR systems geared toward increased commitment and employee involvement can have a dramatic impact on organizational outcomes. Terms such as commitment-oriented HR systems, high-performance work systems, high-involvement HRM, and the like exude a connotation of extensive investment in, and reliance on, employees. This article first reviews the ‘HR architecture’ to provide a backdrop for our discussion of employment subsystems and changing forms of employment. Second, it examines the implications of globalization, strategy, and managing knowledge flows for how companies structure their portfolio of employment subsystems. Throughout the discussion it offers suggestions for future research.