1st Edition
Fundamentals of Dependable Computing for Software Engineers
Fundamentals of Dependable Computing for Software Engineers presents the essential elements of computer system dependability. The book describes a comprehensive dependability-engineering process and explains the roles of software and software engineers in computer system dependability.
Readers will learn:
- Why dependability matters
- What it means for a system to be dependable
- How to build a dependable software system
- How to assess whether a software system is adequately dependable
The author focuses on the actions needed to reduce the rate of failure to an acceptable level, covering material essential for engineers developing systems with extreme consequences of failure, such as safety-critical systems, security-critical systems, and critical infrastructure systems. The text explores the systems engineering aspects of dependability and provides a framework for engineers to reason and make decisions about software and its dependability. It also offers a comprehensive approach to achieve software dependability and includes a bibliography of the most relevant literature.
Emphasizing the software engineering elements of dependability, this book helps software and computer engineers in fields requiring ultra-high levels of dependability, such as avionics, medical devices, automotive electronics, weapon systems, and advanced information systems, construct software systems that are dependable and within budget and time constraints.
Introduction
The Elements of Dependability
The Role of the Software Engineer
Our Dependence on Computers
Some Regrettable Failures
Consequences of Failure
The Need for Dependability
Systems and Their Dependability Requirements
Where Do We Go from Here?
Organization of This Book
Dependability Requirements
Why We Need Dependability Requirements
The Evolution of Dependability Concepts
The Role of Terminology
What Is a System?
Requirements and Specification
Failure
Dependability and Its Attributes
Systems, Software and Dependability
Defining Dependability Requirements
As Low as Is Reasonably Practicable (ALARP)
Errors, Faults, and Hazards
Errors
The Complexity of Erroneous States
Faults and Dependability
The Manifestation of Faults
Degradation Faults
Design Faults
Byzantine Faults
Component Failure Semantics
Fundamental Principle of Dependability
Anticipated Faults
Hazards
Engineering Dependable Systems
Dependability Analysis
Anticipating Faults
Generalizing the Notion of Hazard
Fault Tree Analysis
Failure Modes, Effects and Criticality Analysis
Hazard and Operability Analysis
Dealing with Faults
Faults and Their Treatment
Fault Avoidance
Fault Elimination
Fault Tolerance
Fault Forecasting
Applying the Four Approaches to Fault Treatment
Dealing with Byzantine Faults
Degradation Faults and Software
Impact on Software
Redundancy
Redundant Architectures
Quantifying the Benefits of Redundancy
Distributed Systems and Fail Stop Computers
Software Dependability
Faults and the Software Lifecycle
Formal Techniques
Verification by Model Checking
Correctness by Construction
Approaches to Correctness by Construction
Correctness by Construction — Synthesis
Correctness by Construction — Refinement
Software Fault Avoidance
Software Fault Elimination
Managing Software Fault Avoidance and Elimination
Misconceptions about Software Dependability
Software Fault Avoidance in Specification
The Role of Specification
Difficulties with Natural Languages
Specification Difficulties
Formal Languages
Model-Based Specification
The Declarative Language Z
A Simple Example
A Detailed Example
Overview of Formal Specification Development
Software Fault Avoidance in Implementation
Implementing Software
Programming Languages
An Overview of Ada
Programming Standards
Correctness by Construction — SPARK
Software Fault Elimination
Why Fault Elimination?
Inspection
Testing
Software Fault Tolerance
Components Subject to Design Faults
Issues with Design Fault Tolerance
Software Replication
Design Diversity
Data Diversity
Targeted Fault Tolerance
Dependability Assessment
Approaches to Assessment
Quantitative Assessment
Prescriptive Standards
Rigorous Arguments
Applicability of Argumentation
Bibliography
Exercises appear at the end of each chapter.
Biography
John Knight is a professor of computer science at the University of Virginia. Prior to joining the University of Virginia, he was with NASA’s Langley Research Center. Dr. Knight has been a recipient of the Harlan D. Mills award from the IEEE Computer Society and the Distinguished Service award from ACM’s Special Interest Group on Software Engineering (SIGSOFT). He is an editorial board member of the Empirical Software Engineering Journal and was editor of the IEEE Transactions on Software Engineering from January 2002 to December 2005.
The book is an important addition to one’s bookshelf. … it is insightful, close to faultless, and a wonderful reference. Read it from front to back and cite it in your proposals and professional and scholarly papers. … This book can and should be taught as part of an undergraduate or graduate software engineering program. I wish it had been available when I was setting up a graduate software engineering program … .
—Larry Bernstein, Computing Reviews, June 2012This book takes full advantage of the extensive work that has been undertaken over many years on the creation of a rich set of system dependability concepts. John Knight makes excellent use of these concepts in producing a very well-argued and comprehensive account, aimed squarely at software engineers, of the variety of dependability issues they are likely to find in real systems and of the strategies that they should use to address these issues. Appropriately qualified students who study this book thoroughly and computer professionals seeking a greater understanding of the various dependability-related problems that they have encountered already in their careers should gain much from this book. I therefore take great pleasure in enthusiastically recommending it to both classes of reader.
—From the Foreword by Brian Randell, Newcastle University, UK