networks of arbitrary geometries and large dimensions. The networks are unreliable and part arrivals and departures are random. The goal is to compute, among others, throughput, inventories, and downtimes and design the network optimally. The accuracy of the model is almost perfect and its computational speed far superior to other existing models. He and his coworkers developed a software package that has been used by Greek companies and the Ford Motor Company in Great Britain. The package has also been exhibited at the International Fair of Thessaloniki, Greece. This model handles fast dynamics via analysis and slow dynamics via simulation. Until its development practitioners in the field used simulation for daily production planning, which demands hours or even days and, thus, is useless, or analysis which is unacceptably inaccurate. The model has run times of seconds or at most minutes and accuracies ranging above 95%. An executive of Ford Motor, Dagenham, England called this model 'miraculous' after they used it in the production of the Jag uar engines. This work is presented in the book: Kouikoglou and Phillis, 'Hybrid Simulation Models of Production Networks,' Kluwer, New York, 2001. The book was very well received by reviewers and peers. • In the same field of automated and flexible manufacturing engineering, he performed pioneering work by solving two fundamental problems using fuzzy logic, flexibility assessment of complex production systems and flow and routing control of queues. He and his coworkers have again developed practical and user-friendly software packages. The fuzzy methodology was novel in both problems and led to realistic and simple solutions. • His work on queuing control signals is a ground breaking application of fuzzy logic. Traditional techniques, such as dynamic programming, have limited effectiveness, if at all, in complex or non-Markovian networks. The new methodology on the other hand has already provided solutions to unsolved problems and promises to open a new avenue in queue control. This work was summarized in the text: Z. Runtong, Y. A. Phillis, and V. S. Kouikoglou, "Fuzzy Control of Queuing Systems," Springer, New York, 2004. • Definition and assessment of sustainable development. This is a field of the utmost importance in economics and politics. He has developed a practical mathematical model, called SAFE (Sustainability Assessment by Fuzzy Evaluation), which can be used by decision makers and politicians to assess the sustainability of a country or region and detect those aspects that can improve it. Sustainable development is a fashionable term among politicians, economists, and environmentalists, but they all speak of different things. Now, for the first time a framework is developed incorporating a large number of parameters which define and assess sustainability numerically, via statistical analysis and fuzzy logic. It can be used to assess the sustainability of an economy and lead to decisions that improve it. The model is one of the first of its kind in a field where mathematical models were almost absent. A ranking of most countries of the world according to sustainability appears on a regular basis annually in the website www.sustainability.tuc.gr . This material is the basis of courses that he has taught at UCLA, the Technical University of Crete, University of South Florida, and the University of Denver. Numerous researchers have cited and are using SAFE throughout the world. Examples of applications of SAFE by other practitioners to assess the sustainability of: agriculture in Caucha Valley, Colombia o