The competitive environment of today has generated an increased interest in flexibility as a response mechanism. While the potential benefits of flexibility are familiar, the concept of flexibility itself is not well-understood. Neither practitioners nor academics agree upon, or know, how flexibility can be gauged or measured in its totality. Consequently, this study seeks to provide a framework for understanding this complex concept and to create a theoretical foundation for the development of generalizable measures for manufacturing flexibility. With this objective in mind, we first critically examine diverse streams of literature to define four constituent elements of flexibility: range number (R-W), range-heterogeneity (R-H), mobility (M), and uniformity (U). The R-H element is new, and has not been proposed before in prior literature. These four elements can be applied to consistently define different types or dimensions of flexibility. Definitions for 10 flexibility dimensions pertaining to manufacturing are thus obtained. These definitions serve a dual purpose. First, they capture the domain of flexibility. Second, we show in this study how these definitions can be used to generate scale items, thereby facilitating the development of generalizable manufacturing flexibility measures. Several research avenues that can be explored once such measures are developed are also highlighted. (C) 1999 Elsevier Science B.V. All rights reserved.