[Excerpt] Strategic human resource management refers to the pattern of planned human resource deployments and activities intended to enable an organization to achieve its goals (Wright & McMahan, 1992). It involves all of the activities that are implemented by an organization to affect the behavior of individuals in an effort to implement the strategic needs of a business. Over the last decade or so, the field of strategic human resource management has witnessed a progression through a number of stages, including a) initial excitement and energy around the convincing argument that HR practices should be considered as a system that, when implemented appropriately, can enhance organizational performance; b) empirical tests of this argument, and c) critiques of the growing field accompanied by propositions for how thinking on the topic can be expanded and improved. Of the critiques that have been levied at the field, the most common contend that the “black box” through which HRM practices are thought to impact organizational performance remains insufficiently specified. Less common, but no less valuable, are critiques surrounding the conceptualization and measurement of fit or alignment, and the need to identify the boundary conditions that influence the effectiveness of “high performance” HRM systems. Even more critiques and proposed theoretical extensions to the field are likely, as it is through such endeavors that we will improve upon and advance our science (cf. Reichers & Schneider, 1990). In this chapter, we introduce and discuss another potential critique of the SHRM field, and, in so doing, hope to illuminate a number of important research questions for the future. In particular, we are concerned with the lack of attention which has been paid to variability within SHRM research. By variability we mean variability at all relevant levels of analysis, but particularly variability within organizations (i.e., individual and group levels). It is our contention that by failing to examine the potential role of variability in SHRM research, we miss a very interesting and important part of the picture.