Robust design using a hybrid-cellular-evolutionary and interval-arithmetic approach: a reliability application

Sensitivity analysis is a technique by which one can determine, with good approximation, whether a system will work within the specification limits when the input vary between their limits. Although this type of analysis, from input to output, can provide useful information to the decision-maker, we present an approach based on the use of Cellular Evolutionary Strategies and Interval Arithmetic in which the inverse problem can be solved. That is, we move from output to input: starting with output range specifications, we infer the maximum uncertainty or variability that can be exhibited by the input parameters. The approach used is an indirect method based on optimisation instead of a direct method based on mapping from the output into the input space. The proposed approach is illustrated by computational examples applied to a reliability complex system. Results are compared with those obtained using a general non-linear optimisation package. (C) 2002 Elsevier Science Ltd. All rights reserved.