This book contains the proceedings of the 1989 Ada-Europe conference. These meetings constitute the most significant events in this field within Europe, and attract delegates from around the world. The theme of this year's conference is design methods; this is of major importance since both Ada compilers and the applications built with Ada are huge. Papers in this volume, which have all been carefully refereed, study the design methods within Ada, and how they may need to be augmented with additional methods and tools where necessary. They make informed and essential reading for all involved in the use of Ada in industry and research.