0 e This is the proceedings of the first annual symposium of the Safety-critical Systems Club (The Watershed Media Centre, Bristol, 9-11 February 1993), which provided a forum for exploring and discussing ways of achieving safety in computer systems to be used in safety-critical industrial applications. The book is divided into three parts, which correspond with the themes of the three days of the symposium. The first - Experience from Around Europe - brings together information on developments in safety-critical systems outside the UK. The second - Current Research - consists of papers on large projects within the UK, which involve collaboration between academia and industry, providing techniques and methods to enhance safety. The final part - Achieving and Evaluating Safety - explores how methods already in use in other domains may be applied to safety, and examines the relationships between safety and other attributes such as quality and security. The papers identify the current problems and issues of interest in the field of safety-critical software-based systems, and provide valuable up-to-date material for those in both academia and industry. The academic will benefit from information about current research complimentary to his own, and the industrialist will learn of the technologies which will soon be available and where to find them.

The programme for the Second Safety-critical Systems Symposium was planned to examine the various aspects of technology currently employed in the design of safety-critical systems, as well as to emphasise the importance of safety and risk management in their design and operation. assessment There is an even balance of contributions from academia and industry. Thus, industry is given the opportunity to express its views of the safety-critical domain and at the same time offered a glimpse of the technologies which are currently under development and which, if successful, will be available in the medium-term future. In the field of technology, a subject whose importance is increasingly being recognised is human factors, and there are papers on this from the University of Hertfordshire and Rolls-Royce. Increasingly, PLCs are being employed in safety-critical applications, and this domain is represented by contributions from Nuclear Electric and August Computers. Then there are papers on maintainability, Ada, reverse engineering, social issues, formal methods, and medical systems, all in the context of safety. And, of course, it is not possible to keep the 'new' technologies out of the safety-critical domain: there are papers on neural networks from the University of Exeter and knowledge-based systems from ERA Technology.

This book contains the Proceedings of the 6th Safety-critical Systems Sympo sium, the theme of which is Industrial Perspectives. In accordance with the theme, all of the chapters have been contributed by authors having an industrial af filiation. The first two chapters reflect half-day tutorials - Managing a Safety-critical System Development Project and Principles of Safety Management - held on the first day of the event, and the following 15 are contributed by the presenters of papers on the next two days. Following the tutorials, the chapters fa~l into five sub-themes - the session titles at the Symposium. In the first of these, on 'Software Development Tech nology', Trevor Cockram and others report on the industrial application of a requirements traceability model, Paul Bennett on configuration management in safety-critical systems, and Brian Wichmann on Ada. The next 5 chapters are on 'Safety Management'. In the safety domain, the fundamental business of management is increasingly being addressed with respect not merely to getting things done, but also to controlling the processes by which they are done, the risks involved, and the need not only to achieve safety but to demonstrate that it has been achieved. In this context, Gustaf Myhrman reveals recent developments for safer systems in the Swedish De fence, and Shoky Visram reports on the management of safety within a large and complex Air Traffic Control project.

Safety-Critical Systems (SCS) are increasingly present in people's daily activities. In the means of transport, in medical treatments, in industrial processes, in the control of air, land, maritime traffic, and many other situations, we use and depend on SCS. The requirements engineering of any system is crucial for the proper development of the same, and it becomes even more relevant for the development of SCS. Requirements Engineering is a discipline that focuses on the development of techniques, methods, processes, and tools that assist in the design of software and systems, covering the activities of elicitation, analysis, modeling and specification, validation, and management of requirements. The complete specification of system requirements establishes the basis for its architectural design. It offers a description of the functional and quality aspects that should guide the implementation and system evolution. In this book, we discuss essential elements of requirements engineering applied to SCS, such as the relationship between safety/hazard analysis and requirements specification, a balance between conservative and agile methodologies during SCS development, the role of requirements engineering in safety cases, and requirements engineering maturity model for SCS. This book provides relevant insights for professionals, students, and researchers interested in improving the quality of the SCS development process, making system requirements a solid foundation for improving the safety and security of future systems.

Safety-critical systems, in the sense of software-based systems used in safety critical applications, are 'high-tech'. They are products of modern technology. Their effective, efficient and safe functioning depends not only on the devel opment of the right technologies but also on the right use of them. The safety of a system may be compromised not only by faults in the system but also by the use in the first place of an unreliable, unsafe, or unproved technology in its development. The key to the development and use of both technologies and systems is the human being. Until recently, the importance of human involvement, other than at the direct operational level, was hardly admitted. But now the unreliability of humans is recognised, as is the potential for latent faults to be introduced into systems at any point in their life cycles, by all who are in volved with them, including designers and strategic decision makers.

Safety-critical systems, by definition those systems whose failure can cause catastrophic results for people, the environment, and the economy, are becoming increasingly complex both in their functionality and their interactions with the environment. Unfortunately, safety assessments are still largely done manually, a time-consuming and error-prone

This book constitutes the refereed proceedings of the Third International Workshop on Formal Techniques for Safety-Critical Systems, FTSCS 2014, held in Luxembourg, in November 2014. The 14 revised full papers presented together with two invited talks were carefully reviewed and selected from 40 submissions. The papers address various topics related to the application of formal and semi-formal methods to improve the quality of safety-critical computer systems.

Safety Critical Systems Handbook: A Straightfoward Guide to Functional Safety, IEC 61508 (2010 Edition) and Related Standards, Including Process IEC 61511 and Machinery IEC 62061 AND ISO 13849, Third Edition, offers a practical guide to the functional safety standard IEC 61508. The book is organized into three parts. Part A discusses the concept of functional safety and the need to express targets by means of safety integrity levels. It places functional safety in context, along with risk assessment, likelihood of fatality, and the cost of conformance. It also explains the life-cycle approach, together with the basic outline of IEC 61508 (known as BS EN 61508 in the UK). Part B discusses functional safety standards for the process, oil, and gas industries; the machinery sector; and other industries such as rail, automotive, avionics, and medical electrical equipment. Part C presents case studies in the form of exercises and examples. These studies cover SIL targeting for a pressure let-down system, burner control system assessment, SIL targeting, a hypothetical proposal for a rail-train braking system, and hydroelectric dam and tidal gates. - The only comprehensive guide to IEC 61508, updated to cover the 2010 amendments, that will ensure engineers are compliant with the latest process safety systems design and operation standards - Helps readers understand the process required to apply safety critical systems standards - Real-world approach helps users to interpret the standard, with case studies and best practice design examples throughout

This book provides professionals and students with practical guidance for the development of safety-critical computer-based systems. It covers important aspects ranging from complying with standards and guidelines to the necessary software development process and tools, and also techniques pertaining to model-based application development platforms as well as qualified programmable controllers. After a general introduction to the book’s topic in chapter 1, chapter 2 discusses dependability aspects of safety systems and how architectural design at the system level helps deal with failures and yet achieves the targeted dependability attributes. Chapter 3 presents the software development process which includes verification and validation at every stage, essential to the development of software for systems performing safety functions. It also explains how the process helps in developing a safety case that can be independently verified and validated. The subsequent chapter 4 presents some important standards and guidelines, which apply to different industries and in different countries. Chapter 5 then discusses the steps towards complying with the standards at every phase of development. It offers a guided tour traversing the path of software qualification by exploring the necessary steps towards achieving the goal with the help of case studies. Chapter 6 highlights the application of formal methods for the development of safety systems software and introduces some available notations and tools which assist the process. Finally, chapter 7 presents a detailed discussion on the importance and the advantages of qualified platforms for safety systems application development, including programmable controller (PLC) and formal model-based development platforms. Each chapter includes case studies illustrating the subject matter. The book is aimed at both practitioners and students interested in the art and science of developing computer-based systems for safety-critical applications. Both audiences will get insights into the tools and techniques along with the latest developments in the design, analysis and qualification, which are constrained by the regulatory and compliance requirements mandated by the applicable guides and standards. It also addresses the needs of professionals and young graduates who specialize in the development of necessary tools and qualified platforms.

The Safety Critical Systems Handbook: A Straightforward Guide to Functional Safety: IEC 61508 (2010 Edition), IEC 61511 (2015 Edition) and Related Guidance, Fifth Edition presents the latest guidance on safety-related systems that guard workers and the public against injury and death, also discussing environmental risks. This comprehensive resource has been fully revised, with additional material on risk assessment, cybersecurity, COMAH and HAZID, published guidance documents/standards, quantified risk assessment and new worked examples. The book provides a comprehensive guide to the revised IEC 61508 standard as well as the 2016 IEC 61511. This book will have a wide readership, not only in the chemical and process industries, but in oil and gas, power generation, avionics, automotive, manufacturing and other sectors. It is aimed at most engineers, including those in project, control and instrumentation, design and maintenance disciplines. - Provides the only comprehensive guide to IEC 61508 and 61511 (updated for 2016) that ensures engineers are compliant with the latest process safety systems design and operation standards - Presents a real-world approach that helps users interpret the standard, with new case studies and best practice design examples using revised standards - Covers applications of the standard to device design