Classification: LCC TA169 .H68 2021 (print) | LCC TA169 (ebook) | DDC
620/.00452–dc23
LC record available at https://lccn.loc.gov/2020016182
LC ebook record available at https://lccn.loc.gov/2020016183
Cover Design: Wiley
Cover Images: System reliability theory Courtesy of Marvin Rausand,
Abstract purple and pink polygonal © Tuomas Lehtinen/Getty Images
To Hella; Guro and Idunn; and Emil and Tiril
To: Nicolas; Penelope; and Garance
Preface
This book provides a basic, but rather comprehensive introduction to system reliability theory and the main methods used in reliability analyses. System reliability theory is used in many application areas. Some of these are illustrated in the book as examples and problems.
Main Changes from the Second Edition
Readers who are familiar with the second edition (Rausand and Høyland 2004) will find that the third edition is a major update and that most chapters have been rewritten. The most significant changes include:
A new Chapter 2 defining the study object and its functions and operating context is included. System modeling by reliability block diagrams is introduced and the concept of complexity is discussed.
A new Chapter 3 defining and discussing the concepts of failure and fault, together with several associated concepts is added. Two failure analysis techniques are presented.
New component importance metrics are included.
The treatment of dependent failures is significantly extended.
Section 8.8 on complex systems in the second edition is removed from the chapter on Markov analysis where several new models are added.
A new Chapter 2 on preventive maintenance is added. This chapter merges aspects from the previous edition with new models and methods. The presentation is supplemented by Python scripts that are found on the book companion site.
Chapters 11 and 13 in the second edition on life data analysis and Bayesian reliability analysis are totally rewritten. The statistical program system R is extensively used in the presentation.
Chapter 12 in the second edition on accelerated testing has been removed, but parts of the chapter are moved to the chapter on reliability data analysis.
The end of chapter problems have been revised and new problems are added.
Most of the appendices are removed. The content is partly integrated in the text and partly obsolete because of the use of R.
An author index is provided.
Supplementary Information on the Internet
An immense amount of relevant information is today available on the Internet, and many of the topics in this book may be found as books, reports, lecture notes, or slides written by lecturers from many different universities. The quality of this information is varying and ranging from very high to rather low, the terminology is often not consistent, and it may sometimes be a challenge to read some of these Internet resources. The reader is encouraged to search the Internet for alternative presentations and compare with the book. This way, new ideas and increased insight may spring up.
With the abundance of free information on the Internet, it is pertinent to ask whether a traditional book is really needed. We strongly believe that a book may provide a more coherent knowledge and we have tried to write the book with this in mind.
Intended Audience
The book is written primarily for engineers and engineering students, and the examples and applications are related to technical systems. There are three groups that constitute our primary audience:
The book was originally written as a textbook for university courses in system reliability at the Norwegian University of Science and Technology (NTNU) in Trondheim. This third edition is based on experience gained from use of the first two editions, at NTNU and many other universities, and also from using the book in a wide range of short courses for industry.
The second is to be a guide for engineers and consultants who carry out practical system reliability analyses of technical systems.
The third is to be a guide for engineers and consultants in areas where reliability is an important aspect. Such areas include risk assessment, systems engineering, maintenance planning and optimization, logistics, warranty engineering and management, life cycle costing, quality engineering, and several more. It may be noted that several of the methods used in artificial intelligence and machine learning are treated in this book.
Readers should have a basic course in probability theory. If not, you should get hold of an introductory textbook in probability and statistics to study in parallel with reading this book. A multitude of relevant lecture notes, slides, and reports are also available on the Internet. Brief guidance to relevant sources is provided on the book companion site.
Aims and Delimitation
The book is intended to give a thorough introduction to system reliability. Detailed objectives and associated delimitations are found in Section 1.8. The study object may range from a single component up to a rather complicated technical system. The study object is delimited to items that are mainly based on mechanical, electrical, or electronic technology. An increasing number of modern items have a lot of embedded software. Functions that earlier were carried out by mechanical and electromechanical technology are today software‐based functions. A family car that was built when the second edition was published is, for example, very different from a modern car, which is sometimes characterized as a “computer on wheels.” Software reliability is different from hardware reliability in many ways and we, therefore, consider pure software reliability to be outside the scope of the book. Many software‐based functions may, however, be treated with the methods presented.
Many modern systems are getting more and more complex. Chapter 2 introduces three categories of systems: simple, complicated, and complex systems. Complex systems are here defined to be systems that do not meet all the requirements of the Newtonian–Cartesian paradigm and therefore cannot be adequately analyzed with traditional methods. The complexity theory and the approaches to study complex systems is considered to be outside the scope of the book.
The objective of this book is to help the reader to understand the basic theory of system reliability and to become familiar with the most commonly used analytical methods. We have focused on producing reliability results by hand‐calculation, sometimes assisted by simple R and Python programs. When you carry out practical reliability analyses of large systems, you usually need some special computer programs, such as fault tree analysis programs and simulation programs. A high number of programs are available on