27/09/2024 News
Reliability Assessment of Safety and Production Systems: a reference work for methods, GRIF for exercises
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In 2021, Jean-Pierre Signoret, a key figure in reliability engineering sciences and the originator of the GRIF software suite, published a reference book on reliability: "Reliability Assessment of Safety and Production Systems -Analysis, Modelling, Calculations and Case Studies." This state-of-the-art work, comprising 38 chapters, is intended for industry professionals, engineering schools, and universities. It has been a success! Over 40,000 chapters have already been downloaded from the publisher's website (Springer). The book includes both theory and practical exercises to be performed with GRIF. |
What motivated you to write this over 900-page book on reliability?
Jean-Pierre Signoret: I wanted to share over 50 years of expertise in a field that has evolved significantly, transitioning from the original "reliability" to the current "functional safety". Additionally, I aimed to highlight the French perspective on the matter, promoted by the Institut de Maîtrise des Risques (IMdR) which is much more scientific than in other countries.
During my career, I often found it challenging not to have a reference book that conveyed this vision, especially in my interactions with English-speaking subcontractors from Elf and later Total (now TotalEnergies). Hence, I decided to take advantage of my retirement to fill this gap and produce a tool that is both theoretical and educational. Alain Leroy, who also spent his entire career in functional safety, including a few years at Total, was on board. We contacted several publishers in advance to ensure our work would not be in vain, and Springer supported us. To give the book "Reliability Assessment of Safety and Production Systems - Analysis, Modelling, Calculations and Case Studies" a better chance of becoming an international reference, we decided to write it in English.
"I wanted to share over 50 years of expertise in a field that has evolved significantly, transitioning from the original "reliability" to the current "functional safety."
This book is closely related to GRIF, the software suite you developed for TotalEnergies' needs in the early 1980s. Why?
Jean-Pierre Signoret: Our book is a state-of-the-art overview of functional safety. It exhaustively covers all the methods to ensure that systems operate as intended, meaning without causing accidents—safe for people, reliable for installations—while remaining profitable. Among the topics covered are: a general overview of functional safety studies, basic concepts, risk identification through qualitative approaches (HAZOP, FMEA, etc.), modeling of industrial systems through static approaches (fault tree, reliability diagram), sequential approaches (event trees, bow-tie diagrams, etc.), and dynamic approaches (Markov graphs, Petri nets), probabilistic calculations (analytical or Monte Carlo simulation), consideration of common cause failures and uncertainties, collection and development of reliability data, functional safety standardization, and safety instrumented systems (SIS). Developed from "producer to consumer," GRIF is a tool that allows transitioning from scientific methods to calculations and then to result analysis. Hence, the interest in offering a free demonstration version of GRIF to readers so they can take their first steps through exercises and understand the importance of the software suite.
"Developed from "producer to consumer,"
GRIF is a tool that allows transitioning from scientific methods to calculations and then to result analysis."
More than 40,000 chapters have already been downloaded. Do you consider this a success?
It is rather proof that there was truly a need for a reference book. And especially a pedagogical book that is neither a mathematics treatise nor a stack of categorical prescriptions. Anyone with a minimum of common sense and scientific and mathematical knowledge should be able to progress with this book.
A final word?
Anticipation is the key word of this book. Often, rules are born from accidents, but today, more than ever, it is necessary to anticipate. Functional safety fits into this perspective: identifying and analyzing on paper all the scenarios that could occur, sorting them by probability of occurrence, and then finding solutions to prevent them before they even happen. "Reliability Assessment of Safety and Production Systems - Analysis, Modelling, Calculations and Case Studies" and GRIF are used in many industries but also increasingly by engineering schools and universities. At the request of the Institut National des Sciences Appliquées (INSA) de Toulouse, we are working on a MOOC in French, with four modules and exercises to approach functional safety.
"Reliability Assessment of Safety and Production Systems - Analysis, Modelling, Calculations and Case Studies and GRIF are used in many industries but also increasingly by engineering schools and universities [...] we are working on a MOOC in French, with four modules and exercises to approach functional safety."
After exploring the motivations and details of Jean-Pierre Signoret’s book, we now turn to Gilles Motet, a professor at INSA Toulouse, to understand how this collaboration has led to the development of online training modules on functional safety using the GRIF software.
"This has led us to develop a pedagogy adapted to maintaining the commitment of participants to follow these training courses in complete autonomy"
Gilles Motet – INSA Toulouse
Can you tell us a few words about you?
I'm Gilles Motet, Professor at INSA Toulouse and head of the SEAMOnLine online course platform.
With mainly industrial authors, we have already developed 24 training units of 15 to 20 hours each, i.e. around 400 hours of training, on industrial safety. To date, over 4,200 people from 125 countries have registered on the platform. It is therefore an effective tool for disseminating industrial safety knowledge in its many facets: risks and their treatment, risk analysis and management methods, operating safety, human and organizational safety factors, etc.
This has led us to develop a pedagogy adapted to maintaining the commitment of participants to follow these training courses in complete autonomy (24/7 open platform). We have also developed a method for collaborating with authors whose primary aim is not training, in order to build their units. This will be the subject of a presentation at the LamdaMu24 national risk management conference (October 2024 Bourges).
"With mainly industrial authors, we have already developed 24 training units of 15 to 20 hours each, i.e. around 400 hours of training"
How did you set up this training collaboration with J-P Signoret?
Gilles Motet: I contacted Jean-Pierre Signoret from TPA (TotalEnergies Professeurs Associés) after reading his book "Reliability Assessment of Safety and Production Systems" published by Springer. I appreciated the way in which production requirements were taken into account at the same time as safety requirements, showing that they could be in good agreement, but also the scientific depth with which the subject was dealt with, without sweeping the difficulties under the carpet.
In total, we developed 4 units (in French) of around 20 hours each on the following topics: "Background, concepts and general approach" (Unit 1), "Introduction to quantitative analyses, reliability data and Markovian approach" (Unit 2), "Boolean approach" (Unit 3) and "Monte Carlo simulation and Petri nets" (Unit 4).
This gave us the opportunity to bring these units under the TPA (TotalEnergies Professeurs Associés) banner by signing an INSA de Toulouse/TPA agreement, and to use the demo version of the GRIF software initiated by J-P Signoret and developed by TotalEnergies for our training exercises.
What benefits do you see in this collaboration and the use of GRIF software for your students?
Gilles Motet: In reality, they're not "my students", but people who log on from the four corners of the planet, whenever they want, and who can log off just as quickly if they get bored or discover a difficulty that's too great. So it's up to us to enthuse them, even about difficult subjects.
Face-to-face training very often begins with theoretical knowledge (lectures), followed by practical exercises on paper (TD) and then experiments (TP using tools such as GRIF). On-line training is generally limited to the first 2 stages, with quizzes for TD. This makes it difficult to maintain the commitment of participants in the absence of regular practical stimuli.
In the 4 units developed with Jean-Pierre Signoret, we frequently "turned the tables". The availability of the demo version of the GRIF software enabled Jean-Pierre to design a large number of simple but non-trivial case studies (over 50 in all), using the various functionalities available in the GRIF packages.
"The availability of the demo version of the GRIF software enabled Jean-Pierre to design a large number of simple but non-trivial case studies [...] using the various functionalities available in the GRIF packages."
- Probabilistic calculations to assess availability, reliability and failure rates.
- Cumulative dwell time analysis for average availability and productivity of multi-state systems.
- Modeling of multi-phase systems (operating sequences and periodically tested systems).
- Impact of initial conditions, common failures and maintenance policies.
Fault Tree Analysis (FTA):
- Qualitative and semi-quantitative analysis of minimum cuts.
- Instantaneous and average unavailability calculations (PFDavg for SIS) with temporal aspects.
- Integration of Markov processes driven by ADD.
- Calculation of importance factors, average frequency (PFH for SIS), and failure rate (Vesely).
- Monte Carlo simulation to assess uncertainty.
- Modeling of dynamic aspects that cannot be modeled by Markov and ADD.
- Monte Carlo simulation.
Gilles Motet: These numerous uses of GRIF lead to conclusions that are perceived experimentally, and whose generalization is easier to understand later on, as these experiments have brought home the full value of the theoretical concepts.
TotalEnergies' GRIF team's provision of a demo version is an opportunity for students to have access to industrial software, and to take advantage of the many features offered by GRIF for their training.
We look forward to seeing you on the 4 Units of the SEAMOnLine "System dependability" Module.