A new method for assessing the performance of a robotic system performing a high‐precision task has been developed. The method utilizes an entropy‐based formulation to provide a measure of the reliability of a robotic system with respect to a task specification. The derivation of the proposed technique is presented, including two alternative formulations that differ in terms of their complexity and level of approximation. Methods for combining these measures for complex robotic tasks are detailed. The new method is demonstrated in a case study involving a robotic assembly system, in which the entropy formulation is used to select an optimal system design from a set of alternatives. (c) 1995 John Wiley & Sons, Inc.