The working conference dealt with recent developments in the field of modelling and optimization and with knowledge based decision support systems. This contributed to the realiza- tion of the aims of the working group 7.6 which are: - to promote theoretical research in the field of optimization including mathematical programming and optimal control; -to encourage the development of sophisticated knowledge based systems in which refined optimization models and algorithms are used; - to contribute to the exchange and dissemination of information and collective experience among the inter-...