Estimates of the Operational Reliability of Fire Protection Systems.
Estimates of the Operational Reliability of Fire
Protection Systems.
(223 K)
Bukowski, R. W.; Budnick, E. K.; Schemel, C. F.
Fire Protection Strategies for 21st Century Building and
Fire Codes Symposium. EXTENDED ABSTRACTS. Proceedings.
Society of Fire Protection Engineers and American
Institute of Architects. September 17-18, 2002,
Baltimore, MD, 111-124 pp, 2002 AND International
Conference on Fire Research and Engineering (ICFRE3),
Third (3rd). Proceedings. Society of Fire Protection
Engineers (SFPE), National Institute of Standards and
Technology (NIST) and International Association of Fire
Safety Science (IAFSS). October 4-8, 1999, Chicago, IL,
Society of Fire Protection Engineers, Boston, MA, 87-98
pp, 1999, 2002.
Keywords:
fire research; fire protection engineering; fire
protection; evaluation; fire detection; fire
suppression; reliability; literature reviews;
uncertainty; smoke detectors; sprinklers; sprinkler
systems
Abstract:
Fire protection strategies are designed and installed to
perform specific functions. For example, a fire
sprinkler system is expected to control or extinguish
fires. To accomplish this, the system sprinklers must
open, and the required amount of water to achieve
control or extinguishment must be delivered to the tire
location. A fire detection system is intended to provide
sufficient early warning of a fire for occupant
notification and escape, fire service notification, and
in some cases activation of other fire protection
features (e.g., special extinguishing systems, smoke
management systems). Both system activation (detection)
and notification (alarm) must occur to achieve early
warning. Construction compartmentation is generally
designed to limit the extent of fire spread as well as
to maintain the building's structural integrity as well
as tenability along escape routes for some specified
period of time. In order to accomplish this, the
construction features must be fire "rated" (based on
standard tests) and the integrity of the features
maintained. The reliability of individual fire
protection strategies such as detection, automatic
suppression, and construction compartmentation is
important input to detailed engineering analyses
associated with performance based design. In the context
of safety systems, there are several elements of
reliability, including both operational and performance
reliability. Operational reliability provides a measure
of the probability that a fire protection system will
operate as intended when needed. Performance reliability
is a measure of the adequacy of the feature to
successfully perform its intended function under
specific fire exposure conditions. The former is a
measure of component or system operability while the
latter is a measure of the adequacy of the system
design. The scope of this study was limited to
evaluation of operational reliability due primarily to
the form of the reported data in the literature. In
addition to this distinction between operational and
performance reliability, the scope focused on
unconditional estimates of reliability and failure
estimates in terms of fail-dangerous outcomes. A
discussion of these terms is provided later in the
paper. This paper provides a review of reported
operational reliability and performance estimates for
(1) fire detection, (2) automatic suppression, and to a
limited extent (3) construction compartmentation. In
general, the reported estimates for tire detection are
largely for smoke detection/fire alarm systems;
automatic sprinklers comprise most of the data for
automatic suppression, and compartmentation includes
compartment fire resistance and enclosure integrity. It
should be noted that in some cases the literature did
not delineate beyond the general categories of "fire
detection" or "automatic suppression," requiring
assumptions regarding the specific type of fire
protection system.
Building and Fire Research Laboratory
National Institute of Standards and Technology
Gaithersburg, MD 20899