SAFECOMP '96 contains papers presented at the 15th International Conference on Computer Safety, Reliability and Security held in Vienna, Austria, 23-25 October 1996. The conference aimed to provide an opportunity for technical developers and users to discuss and review their experiences, to consider the best technologies currently available, and to identify the skills and technologies required for the future. SAFECOMP '96 focuses on critical computer applications and is intended as a platform for technology transfer between academia, industry and research institutions. SAFECOMP '96 will be of interest to all those in universities, research institutions, industry and business who want to be well-informed about the current international state of the art in computer safety, reliability and security.

The safe and secure operation ofcomputer systems continues to be the major issue in many applications where there is a threat to people, the environment, investment or goodwill. Such applications include medical devices, railway signalling, energy distribution, vehicle control and monitoring, air traffic control, industrial process control, telecommunications systemsand manyothers. This book represents the proceedings of the 16th International Conference on Computer Safety, Reliability and Security, held in York, UK, 7-10 September 1997. The conference reviews the state ofthe art, experience and new trends in the areas of computer safety, reliability and security. It forms a platform for technology transfer between academia, industry and research institutions. In an expanding world-wide market for safe, secure and reliable computer systems SAFECOMP 97 provides an opportunity for technical developers, users and legislators to exchange and review the experience, to consider the best technologies now available and to identify the skills and technologies required for the future. The papers were carefully selected by the Conference International Programme Committee. The authors of the papers come from twelve different countries. The subjects covered include safe software, safety cases, management & development, security, human factors, guidelines standards & certification, applications & industrial experience, formal methods & models andvalidation, verification and testing. SAFECOMP '97 continues the successful series of SAFECOMP conferences first held in 1979 in Stuttgart. SAFECOMP is organised by the European Workshop on Industrial Computer Systems, Technical Committee 7 on Safety, Security and Reliability (EWICS TC7).

Safety-related computer systems are those which may lead to loss of life, injury or plant and environmental damage. Such systems therefore have to be developed and implemented so that they meet strict require and security because their applications cover ments on safety, reliability nearly all areas of daily life and range from controlling and monitoring industrial processes, through robotics and power generation, to transport systems. Highly reliable electronic systems for safety-related applications represent an area in which industry has been involved for many years and which is now gaining increasing importance in academia. Their relevance also results from an increased perception of safety by society. Therefore, not only are technicians involved in this area, but psycho logical and sociological aspects also play a major role. Dealing with safety-related systems we have to consider the whole lifecycle of these systems, starting from specification up to implementation, assessment and operation. All those issues mentioned above are covered in this book, which represents the proceedings of the 14th International Conference on Computer Safety, Reliability and Security, SAFECOMP '95, held in Belgirate, Italy, 11-13 October 1995. The conference continues the series of SAFECOMP conferences which was originated by the European Workshop on Industrial Computer Systems, Technical Committee 7 on Safety, Security and Reliability (EWICS TC7) and reflects the state of the art, experience and new trends in the area of safety-related computer systems.

The European Commission emphasizes, in its Fifth Research Framework, the “. . . emerging generic dependability requirements in the information society, stemming both from the ubiquity and volume of embedded and networked systems and services as well as from the global and complex nature of large scale information and communication infrastructures, from citizens, administrations and business in terms of technologies, tools, systems, applications and services". The series of Conference on Computer Safety, Reliability, and Security (Safecomp) contributes to satisfy these requirements by reviewing the state of the art, experiences, and new trends in the relevant scientific and industrial areas. Safecomp is intended to be a platform for technology transfer among academia, industry, and research institutions, providing the opportunity for exchange of ideas, opinions, and visions among experts. This year Safecomp celebrates the 20th anniversary, its first Conference having been organized in Stuttgart by EWICS (European Workshop on Industrial Computer Systems) in 1979, and we hope these Proceedings will contribute to the celebration by supporting Safecomp aims. The Proceedings include the 25 papers that have been presented orally at the Conference and the full version of the 14 papers that have been presented as posters, all of which were selected from 76 submissions. Papers almost uniformly take up Safecomp topics, dealing with the issues of Safety Assessment and Human Factors, Verification and Validation, Design for Safety, Formal Methods, and Security.

This book constitutes the refereed proceedings of the 19th International Conference on Computer Safety, Reliability, and Security, SAFECOMP 2000, held in Rotterdam, The Netherlands in October 2000.The 33 revised full papers presented together with three invited papers were carefully reviewed and selected for inclusion in the book. The papers are organized in topical sections on verification and validation; software process improvement; formal methods; safety guidelines, standards and certification; hardware aspects; safety assessment; design for safety; and transport and infrastructure.

Computers and their interactions are becoming the characteristic features of our time: Many people believe that the industrial age is going over into the information age. In the same way as life of the beginning of this century was dominated by machines, factories, streets and railways, the starting century will be characterised by computers and their networks. This change naturally affects also the institutions and the installations our lives depend upon: power plants, including nuclear ones, chemical plants, mechanically working factories, cars, railways and medical equipment; they all depend on computers and their connections. In some cases it is not human life that may be endangered by computer failure, but large investments; e. g. if a whole plant interrupts its production for a long time. In addition to loss of life and property one must not neglect public opinion, which is very critical in many countries against major technical defects. The related computer technology, its hardware, software and production process differ between standard applications and safety related ones: In the safety case it is normally not only the manufacturers and the customers that are involved, but a third party, usually an assessor, who is taking care of the public interest on behalf of a state authority. Usually safety engineers are in a better position than their colleagues from the conventional side, as they may spend more time and money on a particular task and use better equipment.

This book constitutes the refereed proceedings of the 24th International Conference on Computer Safety, Reliability, and Security, SAFECOMP 2005, held in Fredrikstad, Norway, in September 2005. The 30 revised full papers were carefully reviewed and selected for inclusion in the book. The papers address all aspects of dependability and survivability of critical computerized systems in various branches and infrastructures.

Theimportanceofsafetyandsecurityisgrowingsteadily.Safetyisaqualityc- racteristic that traditionally has been considered to be important in embedded systems, and security is usually an essential property in business applications. There is certainly a tendency to use software-based solutions in safety-critical applications domains, which increases the importance of safety engineering te- niques. These include modelling and analysis techniques as well as appropriate processes and tools. And it is surely correct that the amount of con?dential data that require protection from unauthorized access is growing. Therefore, security is very important. On the one hand, the traditional motivations for addressing safety and security still exist, and their relevance has improved. On the other hand, safety and security requirements occur increasingly in the same system. At present, many software-based systems interact with technical equipment and they communicate, e.g., with users and other systems. Future systems will more and more interact with many other entities (technical systems, people, the en- ronment). In this situation, security problems may cause safety-related failures. It is thus necessary to address safety and security. It is furthermore required to take into account the interactions between these two properties.

This year we celebrated another anniversary: after 20 years of SAFECOMP in 1999, th this was the 20 SAFECOMP since its inauguration in 1979. This series of events focuses on critical computer applications. It is intended to be a platform for knowledge transfer between academia, industry, and research institutions. Papers are solicited on all aspects of computer systems in which safety, reliability, and security (applied to safety in terms of integrity and availability) are of importance. The 20th SAFECOMP tried to cover new grounds, both thematically and geographically. The previous 19 SAFECOMPs were held in Austria (1989, 1996), France (1987, 1999), Germany (1979, 1988, 1998), Great Britain (1983, 1986, 1990, 1997), Italy (1985, 1995), Norway (1991), Poland (1993), Switzerland (1992), The th Netherlands (2000), and in the USA (1981, 1992), whereas the 20 was held in Hungary. Authors from 13 countries responded to the Call for Papers, and 10 countries were represented in the final program. The proceedings include 20 papers plus 3 invited papers, covering the areas Reliability Assessment and Security, Safety Case and Safety Analysis, Testing, Formal Methods, Control Systems, and this year covering new grounds with a special emphasis on Human Machine Interface, Components off the Shelf, and Medical Systems.