Welcome to Aachen and to the First European Simulation Congress ESC83, a triennial international conference jointly promoted by ASIM/GI, DBSS, SIMS and UKSC. ESC83 is organized by ASIM/GI, . supported by SCS and IMACS, and sponsored by NGI (section for simulation). It takes place at the Karman Auditorium of the Aachen Technical Univer sity, FRG. The aim of ESC83 is to cover all aspects of modeling and simulation in theory and practice, to promote the exchange of knowlewdge and experience between different international research groups in this field, and to strengthen the international contact...