Issue 89: Applying Reliability Based Decision Making to ITM Frequency
By Amanda Kimball
Many National Fire Protection Association (NFPA) fire
protection system standards contain requirements for periodic
inspection, testing, and maintenance (ITM) including NFPA 251, NFPA 72,2
and others. These are often historical requirements that are not based
on ITM data or on observed deficiencies. As NFPA develops new documents
that involve integrated systems, such as NFPA 4,3 the need
for a more data based approach to standardized ITM frequencies will be
important. Further, in the case of water based systems, the required
resources associated with testing are increasing at a rapid rate.
Fire protection systems normally operate in standby mode and become
active in emergency conditions. Failures are not detected until the
system is operated. Regular testing is intended to verify the
operational condition of the equipment.
Currently, testing of fire pumps generates field data.
However, this data is not collected in a standardized manner. The Fire
Protection Research Foundation published a report entitled Fire Pump Field Data Collection and Analysis.4
This project was undertaken with the belief that a collective set of
standardized data could provide a scientific basis for optimum testing
frequencies of the equipment to be included in NFPA 25.
Based on the field data that was available, the objective of this
project underwent changes over the course of its completion. Ultimately,
the project collected and analyzed fire pump field data from a number
of sources and established a framework to collect data for long term
future efforts. The collected data was analyzed for the following: how
well and how frequently the tests provide evidence of existing or
developing problems, the reliability of fire pumps (i.e. what is the
expected impairment time for fire pumps), and the effect of test
frequency on the reliability of fire pumps (i.e. what is the expected
impairment time for fire pumps tested weekly, monthly, and yearly).
In order to establish the relationship between pump test frequency
and the mean time to failure, more data is needed. However, an important
outcome from the analysis of the existing data was that reliability
decreased when fire pumps (both electric and diesel)were tested monthly
as opposed to weekly.
The main recommendations from the project were related to long term
data collection: setting up and maintaining a permanent data collection
web site, developing a solicitation plan for users, and developing data
collection forms for other water based system components (e.g. valves
and pressure regulating devices).
Additionally on the topic of ITM frequencies, the Foundation held a workshop in July of 20125 on
applying reliability based decision making to ITM frequency for fire
protection systems and equipment. The objective of the workshop was to
gather feedback from participants on developing a generalized approach
to ITM frequency, including obtaining, organizing, and analyzing the
data, as well as developing ITM frequency decisions.
During the discussion at the workshop, participants noted several
issues that should be considered by a generalized approach. Poor
management of change was stated as one of drivers of failures, and its
consideration in ITM frequency approach was deemed necessary.
Many participants felt that human and environmental factors also need
to be included in the approach. Specifically, qualifications of
personnel performing ITM activities is a key element of concern, one
which currently depends on the system. The workshop further supported
one of the learning points from the fire pump project, that in many
cases there is an opportunity to collect good data, but it needs to be
standardized in order to analyze and draw conclusions on ITM frequency.
A couple of groups also noted that the definition of failure needs to
be clear as this will drive the data collection format. Participants
expressed the additional need to consider non-fire scenario failures. It
was also noted that in some cases, testing can impact performance when
equipment is not put back into service after the testing. Good design
(i.e. sensors) could address this.
Through these activities, the Foundation realized that developing a
generalized approach for reliability based ITM frequencies for all fire
protection systems may not be possible due to the complexities of the
systems. However, a need still exists for research on the topic of
reliability based ITM, a need which was further highlighted in a workshop held by the Foundation in December of 2013.6
This workshop focused on the issue of design evaluations – if they
should be required and what code or standard should require these
evaluations. The participants of the 2013 workshop agreed that the
frequency of the design evaluations needed to be risk/reliability based.
The Foundation is currently working on an effort to focus on
reliability based ITM frequencies of water based systems. Following the
completion of this effort and based on its results, the approach could
possibly be expanded to other systems as well.
Amanda Kimball is with the Fire Protection Research Foundation
NFPA 25, Standard for the Inspection, Testing, and Maintenance of Water-Based Fire Protection Systems, National Fire Protection Association, Quincy, MA, 2014.
NFPA 72, National Fire Alarm and Signaling Code, National Fire Protection Association, Quincy, MA, 2013.
NFPA 4, Standard for Integrated Fire Protection and Life Safety System
Testing, National Fire Protection Association, Quincy, MA, 2015.
Pennel, G. "Fire Pump Field Data Collection and Analysis," Fire Protection Research Foundation, Quincy, MA, 2012.
Anon., "Guide to Applying Reliability Based Decision Making to ITM
Frequency for Fire Protection Systems and Equipment -Workshop Summary,"
Fire Protection Research Foundation, Quincy, MA, 2013.
Anon., "Addressing the Performance of Sprinkler Systems: NFPA 25 and
Other Strategies - Workshop Summary," Fire Protection Research
Foundation, Quincy, MA, 2014.
3rd Quarter 2013 – Fire Protection Inspection, Testing, and Maintenance and Building Fire Risk – Francisco Joglar, Ph.D
This article describes how inspection, testing, and maintenance of fire
protection can be incorporated into a building fire risk model so that
such activities can be managed on a performance-based approach in
specific applications. The author defines "fire risk” for the purpose of
this article as a quantitative measure of the potential for realization
of unwanted fire consequences. He also explains how maintenance issues
factor into the risk equation. READ MORE
4th Quarter 2012 -- Bridging Installation Standards and Fire Protection Engineering – Kathleen Almand, P.E., FSFPE
What is the role of codes and standards in the future education of a
fire safety (or fire protection) engineer? How does a legacy of fire
safety principles inherent in prescriptive codes and standards enable
and complement an increasingly capable fire safety engineering
profession? Kathleen Almand explains how the Fire Protection Research
Foundation, the National Fire Protection Association’s (NFPA’s)
independent research affiliate, works to help answer these questions. READ MORE
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