Last month, Wiley was proud to publish Uncertainty in Risk Assessment: The Representation and Treatment of Uncertainties by Probabilistic and Non-Probabilistic Methods by authors Terje Aven, Enrico Zio, Piero Baraldi and Roger Flage, which explores methods for the representation and treatment of uncertainty in risk assessment.
In providing guidance for practical decision-making situations concerning high-consequence technologies (e.g., nuclear, oil and gas, transport, etc.), the theories and methods studied in Uncertainty in Risk Assessment have wide-ranging applications from engineering and medicine to environmental impacts and natural disasters, security, and financial risk management. The main focus, however, is on engineering applications.
While requiring some fundamental background in risk assessment, as well as a basic knowledge of probability theory and statistics, Uncertainty in Risk Assessment can be read profitably by a broad audience of professionals in the field, including researchers and graduate students on courses within risk analysis, statistics, engineering, and the physical sciences.
Uncertainty in Risk Assessment:
• Illustrates the need for seeing beyond probability to represent uncertainties in risk assessment contexts.
• Provides simple explanations (supported by straightforward numerical examples) of the meaning of different types of probabilities, including interval probabilities, and the fundamentals of possibility theory and evidence theory.
• Offers guidance on when to use probability and when to use an alternative representation of uncertainty.
• Presents and discusses methods for the representation and characterization of uncertainty in risk assessment.
• Uses examples to clearly illustrate ideas and concepts.
Here Statistics Views interviews co-author Enrico Zio about the book. Professor Zio is Director of the Chair in Complex Systems and the Energetic Challenge of the European Foundation for New Energy of Électricité de France (EDF) at Ecole Centrale Paris and Supelec, Professor, President and Rector’s delegate of the Alumni Association and past-Director of the Graduate School at Politecnico di Milano and Adjunct Professor at University of Stavanger. He is also the Chairman of the European Safety and Reliability Association ESRA, member of the scientific committee of the Accidental Risks Department of the French National Institute for Industrial Environment and Risks, member of the Korean Nuclear society and China Prognostics and Health Management society, and past-Chairman of the Italian Chapter of the IEEE Reliability Society.
1. Congratulations on the publication of your book, Uncertainty in Risk Assessment: The Representation and Treatment of Uncertainties by Probabilistic and Non-Probabilistic Methods which has wide-ranging applications from engineering and medicine to environmental impacts and natural disasters, security, and financial risk management. The main focus, however, is on engineering applications. How did the writing process begin? What was it that initiated the project?
Together with Professor Aven, Drs. Baraldi and Flage, we have been conducting research on the problem of treating uncertainty in risk assessment for some years with an engineering attitude that is trying to understand the methods in view of their practical application. In this view, we have challenged ourselves and wrote a number of research papers exploring, interpreting and trying to explaining our understanding. Based on these background explorative works, we have drawn our findings and, again, challenged ourselves in the adventure of explaining the methods and their applications, in a direct and way for pragmatic application, and keeping honesty in highlighting strengths and weaknesses.
2. The book mentions that some fundamental background in risk assessment is acquired, as well as a basic knowledge of probability theory and statistics, Uncertainty in Risk Assessment can be read profitably by a broad audience of professionals in the field, including researchers and graduate students on courses within risk analysis, statistics, engineering, and the physical sciences. Was this always the target audience you had in mind? Who should read the book and why?
When we started the idea of the book, we had it clear in our minds that we could not write a book on the mathematical methods for the representation and treatment of uncertainty, because there are already a number of outstanding books on that, and our interest and competence are not really on that. We knew that we wanted something else: a book that could be of use for risk analysts (researchers, engineers and students) to understand what the different methods offer and, eventually, choose which way to go in the different “situations”.
3. Can you give us a taster on when to use probability and when to use an alternative representation of uncertainty?
You’ll have to pay me for that…of course an “uncertain” amount… You see, the fair concept behind risk assessment is that one is trying to gather the available relevant and “informative” information, put her/his knowledge and intelligently structure the analysis to assess what could happen. It is “guided” crystal ball reading. However, the key point is that the results are eventually used to make decisions, which have great impact on safety and security. Then, one needs to honestly and fairly evaluate what she/he has got in terms of information and knowledge, and formally use it with the soundest and most adequate method: no prejudice, no favouritism there. So, in the book we try to give simple explanations of the meaning of different types of probabilities including interval probabilities, and argue for the need of seeing beyond probabilities to represent uncertainties in certain risk assessment contexts, giving the fundamentals of alternative methods of uncertainty representation, like possibility theory and evidence theory. In doing so, we try to give guidance on when to use probability and when to use an alternative representation of uncertainty, and use a number of examples to illustrate the underlying ideas and concepts.
4. What is it about the area of risk analysis that fascinates you and your co-authors?
We are weird…we get excited about the problems which revolve and involve risk analysis. On one side, we are fascinated by the challenge of “doing it better”: exploiting the information and knowledge in the most intelligent way to respond at the need of a fair evaluation of risk. On the other side, we are professionally engaged by the impact that the research advances in risk analysis can have on the safety and security of us people and the environment we live in.
…we try to give simple explanations of the meaning of different types of probabilities including interval probabilities, and argue for the need of seeing beyond probabilities to represent uncertainties in certain risk assessment contexts, giving the fundamentals of alternative methods of uncertainty representation, like possibility theory and evidence theory. In doing so, we try to give guidance on when to use probability and when to use an alternative representation of uncertainty, and use a number of examples to illustrate the underlying ideas and concepts.
5. Why is this book of particular interest now?
Because, we (risk analysts) are frustrated. We feel comfortable with the maturity of (probabilistic risk assessment) and yet we are “slapped” by catastrophic events that still occur that bring death and devastation: are we doing a good job? Why can’t we foresee these events and better protect from or mitigate them? Come on! The feeling is that we must go beyond; look more, be more intelligent. This is in line with the opportunity of “exploiting” the increased information available, “growing” our knowledge, “being” more intelligent about the use if all this; and “treating” all this “soundly and fairly”.
6. What were your main objectives during the writing process? What did you set out to achieve in reaching your readers?
You know, now that I think about it, maybe we were writing for ourselves in the sense that we were trying to structure and clarify our understanding…hopefully, the readers will appreciate it too!
7. Were there areas of the book that you found more challenging to write, and if so, why?
Oh, the whole thing was quite challenging….from the “positioning” of the message, to the “framing” of it, all the way to the challenge of writing of this topic in a “pragmatic” way.
8. What will be your next book-length undertaking?
After the next ten years of research, I hope that with my co-authors and the other exceptional risk analysts in the world, I will be able to contribute to a book on how to do better risk assessment and management for protecting also AGAINST extreme events. It is a battle that we need to fight.
9. With an educational background in mechanical and nuclear engineering from Politecnico di Milano, UCLA and MIT, what was it that brought you to recognise statistics, probability theory and risk analysis as relevant disciplines in the first place?
When I was a university student, I was fascinating by “failure” (perhaps trying to avoid my personal one) as a fundamental problem in engineered systems. The nuclear engineering specifics did the rest, with the systemic view of the problem, the impact of its consequences and the methodological and practical challenges associated to its solution.
10. You are currently Professor at Ecole Centrale Paris-Supelec and Politecnico di Milano. Please could you tell us about the role of probability and statistics in your teaching?
The role of the related subjects is fundamental within the structure of the courses on risk assessment, which I teach or coordinate, as they provide the sound methodological structure and the feasible technical tools for “exploiting” information and knowledge with the needed intelligence. And, then, of course, there is the importance of statistics on the degree of satisfaction in the courses…
11. Are there people or events that have been influential in your career?
Wow…yes! Definitely! I remember when Professor Marzio Marseguerra organized a seminar at the Nuclear Engineering Department of Politecnico di Milano on the theory of Monte Carlo simulation applied to reliability analysis and risk assessment – that is when I decided my Politecnico di Milano Master thesis, which and where it all started. Professor Marseguerra is, therefore, one influential guide in my professional life, with his passion for research and attention for humans. I, then, had the privilege to receive the same principles influence by Professor George Apostolakis at UCLA and MIT, and benefited from his teaching and preaching on the values of probabilistic risk assessment with a clear overall vision melting theoretical soundness with practical needs: if the method you are proposing makes a difference on the decision I would make on safety, then call me…otherwise don’t bother. I also remember the stimulus received by Professor Dave Okrent at UCLA who once told me to make sure to change subject of research every ten years, at most… And last (only in time), I remember the first time I was “exchanging and making changes” to the first paper with my book co-authors: it was the Easter vacation and I was working at night in a hotel room during my family vacations, trying to express my views and explain them in response to Professor Terje Aven’s strong and direct challenges: since then, Professor Aven has been a force driving my enthusiasm and the young Drs. Baraldi and Flage a motivation to remain passionate.