Several evaluation methods with various types of flexibility have been developed over the years to evaluate various manufacturing systems. However, it is not easy to use them to evaluate the flexibility of manufacturing systems because of three limitations: 1) ambiguous definitions of flexibility, 2) interdependence among various types of flexibility, and 3) mixed use of available and realized flexibility. This paper proposes a new concept of flexibility called comprehensive flexibility. Then it is quantified; it is an integrated performance measure which covers various types of flexibility in manufacturing systems. A case example is presented to illustrate the process of quantifying the proposed measure and interpret the meaning of the measure. (C) 1998 Elsevier Science Ltd. All rights reserved.