Applications of global optimization to process and molecular design

The purpose of this paper is to review some recent results that demonstrate the importance of identifying global optima of MINLP formulations. We present two global optimization 'success stories' based on the application of global optimization techniques to two design problems. The first application deals with the design of just-in-time flowshops. On a collection of nine problem instances with only four degrees of freedom, global optimization provides solutions that average 17% cost savings compared to designs identified earlier in the literature using local search techniques. The second application deals with design at the molecular level and involves a considerably larger design space for identifying a replacement of Freon. The problem is difficult and has been approached by numerous research groups in the past. Global optimization identifies many novel molecular structures. (C) 2000 Elsevier Science Ltd.