This volume contains the papers presented. at the Third IFIP International Working Conference on Dependable Computing for Critical Applications, sponsored by IFIP Working Group 10.4 and held in Mondello (Sicily), Italy on September 14-16, 1992. System developers increasingly apply computers where they can affect the safety and security of people and equipment. The Third IFIP International Working Conference on Dependable Computing for Critical Applications, like its predecessors, addressed various aspects of computer system dependability, a broad term defined as the degree of trust that may justifiably be placed in a system's reliability, availability, safety, security, and performance. Because the scope of the conference was so broad, we hope the presentations and discussions will contribute to the integration of these concepts so that future computer-based systems will indeed be more dependable. The Program Committee selected 18 papers for presentation from a total of 7 4 submissions at a May meeting in Newcastle upon Tyne, UK. The resulting program represented a broad spectrum of interests, with papers from universities, corporations, and government agencies in eight countries. Much diligent work by the Program Committee and the quality of reviews from more than a hundred external referees from around the world, for which we are most grateful, significantly eased the production of this technical program.

The first ESPRIT Basic Research Project on Predictably Dependable Computing Systems (No. 3092, PDCS) commenced in May 1989, and ran until March 1992. The institutions and principal investigators that were involved in PDCS were: City University, London, UK (Bev Littlewood), lEI del CNR, Pisa, Italy (Lorenzo Strigini), Universitiit Karlsruhe, Germany (Tom Beth), LAAS-CNRS, Toulouse, France (Jean-Claude Laprie), University of Newcastle upon Tyne, UK (Brian Randell), LRI-CNRS/Universite Paris-Sud, France (Marie-Claude Gaudel), Technische Universitiit Wien, Austria (Hermann Kopetz), and University of York, UK (John McDermid). The work continued after March 1992, and a three-year successor project (No. 6362, PDCS2) officially started in August 1992, with a slightly changed membership: Chalmers University of Technology, Goteborg, Sweden (Erland Jonsson), City University, London, UK (Bev Littlewood), CNR, Pisa, Italy (Lorenzo Strigini), LAAS-CNRS, Toulouse, France (Jean-Claude Laprie), Universite Catholique de Louvain, Belgium (Pierre-Jacques Courtois), University of Newcastle upon Tyne, UK (Brian Randell), LRI-CNRS/Universite Paris-Sud, France (Marie-Claude Gaudel), Technische Universitiit Wien, Austria (Hermann Kopetz), and University of York, UK (John McDermid). The summary objective of both projects has been "to contribute to making the process of designing and constructing dependable computing systems much more predictable and cost-effective." In the case of PDCS2, the concentration has been on the problems of producing dependable distributed real-time systems and especially those where the dependability requirements centre on issues of safety and/or security.