Provably Correct Systems

As computers increasingly control the systems and services we depend upon within our daily lives like transport, communications, and the media, ensuring these systems function correctly is of utmost importance. This book consists of twelve chapters and one historical account that were presented at a workshop in London in 2015, marking the 25th anniversary of the European ESPRIT Basic Research project ‘ProCoS’ (Provably Correct Systems). The ProCoS I and II projects pioneered and accelerated the automation of verification techniques, resulting in a wide range of applications within many trades and sectors such as aerospace, electronics, communications, and retail. The following topics are covered: An historical account of the ProCoS project Hybrid Systems Correctness of Concurrent Algorithms Interfaces and Linking Automatic Verification Run-time Assertions Checking Formal and Semi-Formal Methods Provably Correct Systems provides researchers, designers and engineers with a complete overview of the ProCoS initiative, past and present, and explores current developments and perspectives within the field.

Computers are gaining more and more control over systems that we use or rely on in our daily lives, privately as well as professionally. In safety-critical applications, as well as in others, it is of paramount importance that systems controled by a computer or computing systems themselves reliably behave in accordance with the specification and requirements, in other words: here correctness of the system, of its software and hardware is crucial. In order to cope with this callenge, software engineers and computer scientists need to understand the foundations of programming, how different formal theories are linked together, how compilers correctly translate high-level programs into machine code, and why transformations performed are justifiable. This book presents 17 mutually reviewed invited papers organized in sections on methodology, programming, automation, compilation, and application.

The market for safe, secure and reliable computer systems is expanding continuously and these Proceedings provide an opportunity to review the growth during the last decade and identify skills and technologies required for continued development in the area. The papers cover the experiences gained from specifying, creating, operating, and licensing computers in safety, security and reliability related applications. There are reviews of guidelines and industrial applications, with a section covering methods and tools used in designing, documenting, analysing, testing and assessing systems dependent on the SAFECOMP factors.

This book focuses on software architecture and the value of architecture in the development of long-lived, mission-critical, trustworthy software-systems. The author introduces and demonstrates the powerful strategy of “Managed Evolution,” along with the engineering best practice known as “Principle-based Architecting.” The book examines in detail architecture principles for e.g., Business Value, Changeability, Resilience, and Dependability. The author argues that the software development community has a strong responsibility to produce and operate useful, dependable, and trustworthy software. Software should at the same time provide business value and guarantee many quality-of-service properties, including security, safety, performance, and integrity. As Dr. Furrer states, “Producing dependable software is a balancing act between investing in the implementation of business functionality and investing in the quality-of-service properties of the software-systems.” The book presents extensive coverage of such concepts as: Principle-Based Architecting Managed Evolution Strategy The Future Principles for Business Value Legacy Software Modernization/Migration Architecture Principles for Changeability Architecture Principles for Resilience Architecture Principles for Dependability The text is supplemented with numerous figures, tables, examples and illustrative quotations. Future-Proof Software-Systems provides a set of good engineering practices, devised for integration into most software development processes dedicated to the creation of software-systems that incorporate Managed Evolution.

As the complexity of embedded computer-controlled systems increases, the present industrial practice for their development gives cause for concern, especially for safety-critical applications where human lives are at stake. The use of software in such systems has increased enormously in the last decade. Formal methods, based on firm mathematical foundations, provide one means to help with reducing the risk of introducing errors during specification and development. There is currently much interest in both academic and industrial circles concerning the issues involved, but the techniques still need further investigation and promulgation to make their widespread use a reality. This book presents results of research into techniques to aid the formal verification of mixed hardware/software systems. Aspects of system specification and verification from requirements down to the underlying hardware are addressed, with particular regard to real-time issues. The work presented is largely based around the Occam programming language and Transputer microprocessor paradigm. The HOL theorem prover, based on higher order logic, has mainly been used in the application of machine-checked proofs. The book describes research work undertaken on the collaborative UK DTI/SERC-funded Information Engineering Dictorate Safemos project. The partners were Inmos Ltd., Cambridge SRI, the Oxford University Computing Laboratory and the University of Cambridge Computer Laboratory, who investigated the problems of formally verifying embedded systems. The most important results of the project are presented in the form of a series of interrelated chapters by project members and associated personnel. In addition, overviews of two other ventures with similar objectives are included as appendices. The material in this book is intended for computing science researchers and advanced industrial practitioners interested in the application of formal methods to real-time safety-critical systems at all levels of abstraction from requirements to hardware. In addition, material of a more general nature is presented, which may be of interest to managers in charge of projects applying formal methods, especially for safety-critical-systems, and others who are considering their use.

Safety-Critical Real-Time Systems brings together in one place important contributions and up-to-date research results in this fast moving area. Safety-Critical Real-Time Systems serves as an excellent reference, providing insight into some of the most challenging research issues in the field.