This paper presents practical methods for computation of disturbance rejection measures, which are useful for assessing the dynamic operability of the process. Using L-1 optimal control theory, we consider the cases of steady-state, frequency-wise and dynamic systems. In comparison to the available methods, the proposed approach ensures that a linear, causal, feedback-based controller exists that achieves the computed bounds and the method also scales well with problem dimensions. (C) 2007 Elsevier Ltd. All rights reserved.