By John R. Hall, Jr. | Fire Protection Engineering
The field of fire risk assessment has
been growing by leaps and bounds in the past few years. Every major
international standards-developing organization has a new guide on the
subject, as do many nations.
Fire risk assessment has taken three principal
forms. The oldest is the risk index method, primarily associated with
the insurance industry. These can be thought of as checklists on
steroids: not strong on explicit empirical parameters or fundamental
physics, but arguably quite useful and successful over their
century-plus existence. Next oldest is the classic risk analysis model
(e.g., a fault tree or event tree) converted to fire safety, a mostly or
wholly probabilistic approach. And the newest is probability-weighted
hazard analysis, in which the probabilities are reserved for ignition
and reliability, while physics models are used for everything else.
The first of the globally publicized
probability-weighted hazard analysis models came from a collaboration
between Canada and Australia. The latter effort, centered at Victoria
University of Technology under the direction of co-author Beck, led to
Oddly, given this history, the book does not focus on
probability-weighted hazard analyses but favors stochastic modeling for
most modeling components as its approach to fire risk analysis (not fire
risk assessment because there is also no discussion of evaluation).
Buyer beware: This is an original and useful book, but readers will be
disappointed if they are looking for something different than what the
authors have chosen to address.
Chapter 2 is a conceptual overview of fire
and building safety from fire. Chapter 3 covers the basics of
probability theory. The latter is a bit more detailed than the
corresponding chapter in the SFPE Handbook but stops well short of a full course. The reader will probably find it more useful as a refresher than as a tutorial.
Chapter 4 is a short chapter on the Beta
reliability index, which can be associated with Hkan Frantzich of Lund
University. This is the first published treatment of this increasingly
popular index in a book for the general reader. Chapter 5 covers the
basics of Monte Carlo simulation. It would have been preferable if the
authors included a warning that Monte Carlo is not a substitute for
empirical information on probabilities but rather a practical method for
working with probabilities with limited information or common
Chapter 6 introduces event and fault trees. The oddly titled
Chapter 7 on performance-based optimal design is in a location where one
would expect a transitional chapter and overview of fire risk analysis,
but the chapter does not provide a general conceptual model, settling
for a few paragraphs on criteria, uncertainty and some other topics not
covered elsewhere. The book would have benefited from a stronger
transitional chapter and some integrative concepts for the chapters to
Chapter 8 begins a string of chapters on the modeling of particular
phenomena, in this case fire initiation. With Chapter 9 (on "personal
factors"), these play to the strengths of national fire incident
databases and discuss them at some length. Chapter 10 is on barrier
resistance. It was a little surprising that this chapter did not
reference the work of Teresa Ling and Brady Williamson. Chapter 11 is
about fire growth and the CESARE Risk one-zone model. Chapter 12 is on
smoke spread and combines deterministic and stochastic simulation.
Chapter 13 is on human behavior as handled by a submodel of CESARE Risk.
Chapter 14 is on performance assessment of (active) fire safety
systems, using empirically based probability measures. Chapter 15 is on
fire brigade response, which has historically been the most undertreated
component of these models; the authors' full chapter is most welcome.
Chapters 16-17 complete the book with two
case studies. Like most well-done, well-chosen case studies, these are
very helpful, though there will be a temptation to use them as a
shortcut guide on how to use the general methods in all situations.
Putting it all together, this is a useful
book that will fill an important gap on the engineer's bookshelf, but
it is not a definitive tome for the ages. This book is recommended for
those involved in fire risk assessment and those who would like to
consider using these methods in such assessments, but there is a more
comprehensive and ambitious book still to be written on this subject.
John Hall is with the National Fire Protection Association.