Edinburgh, the Scottish capital, hosted SAFECOMP 2003. Since its establishment, SAFECOMP, the series of conferences on Computer Safety, Reliability and Security, has contributed to the progress of the state of the art in dependable applications of computer systems. SAFECOMP provides ample opportunity to exchange insights and experiences in emerging methods across the borders of different disciplines. SAFECOMP year after year registers new multidisciplinary trends on dependability of computer-based systems. The cross-fertilization between different scientific communities and industry supports the achievement of long-term results contributing to the integration of multidisciplinary experiences in order to improve the design and deployment of dependable computer-based systems. Over the years the participation of industry in SAFECOMP has grown steadily. This emphasizes the importance of technology transfer between academia and industry. SAFECOMP 2003 further sustains the healthy interchange of research results and practical experiences. The SAFECOMP 2003 program consisted of 30 papers selected from 96 submissions from all over the world. SAFECOMP 2003 acknowledges the invited keynote talks enhancing the technical and scientific merit of the conference.