(47bq) A Functional System Approach to Criticality Analysis, Fsca

ABSTRACT

A Functional System Approach to
Criticality Analysis, FSCA.

This paper
will outline and discuss a new and unique approach to physical asset
criticality analysis: Functional System Criticality Analysis (FSCA) and
illustrate key results with two sample case studies.  This approach is
applicable to any type of complex facility or process where process security
and continuity are paramount.  It has consistently identified previously
unknown significant risks that were missed by other methods and analyses such
as HAZOPS, FMA, process reviews, and can quantify the risk potential in
dollars.  A functional system based approach (FSCA) is more efficient than
current methods through analyzing and ranking system risks via system failure
scenarios rather than failure modes at the asset level.  It is an
invaluable tool and approach when risk mitigation is important to assure
overall success balanced against the reality of limited time, capital,
maintenance, and staff budgets. 

The two case
studies featured involve an Envirex ground water
remediation facility, and an industrial RO water treatment system within a
refinery.  Each study had a unique set of evaluation criteria determined
by the client's values and the specific performance, contractual, and
regulatory issues affecting the facilities.  Importantly, in each case
study previously unknown significant system risks were identified, as well as
highly effective mitigating steps. 

Approach:

Several key
principles are foundational to the functional system based approach to
criticality analysis, FSCA:

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A
deep and well structured hierarchy of the asset register, leading to a rigorous
parent/child ratio

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Inclusion
of all valves and pipes (strive for 100 percent asset listing) in the hierarchy

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Uniform
asset levels (every pump is an asset no matter where it is or how big)

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The
grouping of assets into single-purpose functional systems

A very clear
description of the mission statement/priorities is very important in this type
of an analysis.  Whether it is defined as a level of service or a more
numerical set of KPIs, the defined mission of the physical assets under review
will determine the categories evaluated against: safety, environmental,
up-time, product quality, maintenance cost, capital replacement, etc. 
These in turn must also be clearly and uniquely defined from one another on a
severity scale ranging from virtually ?no impact' through to ?worst case' in
the client specific nomenclature.  The next step is to proportion or
allocate a contribution ratio for combining categories into overall
risk.  This will determine, for example,
the relative importance or ranking of a worst case scenario compared against a
scenario with 2 or 3 instances of a slightly lesser consequence.  These can be adjusted to suit a client
philosophical approach. 

With these
principles in place, a risk analysis is then performed at the functional system
level derived from the hierarchy, prior to the asset level. Failure scenarios
and their resulting consequences are evaluated per the evaluation criteria
defined (not failure modes since those are at the asset level).  The
failure scenarios for each functional system define a composite risk space for
each system, and then each system is ranked against all others in terms of
risk. 

Important to
note is that assets within a parent system initially assume the risk ranking of
the parent system.  Thus, systems with highest risk ranking (mission
critical) are then further evaluated at the asset level, employing a suitable
mix of evaluation tools (RCM, FMA, etc) to discern which of the contained
assets pose the highest risks to the mission objective.  Systems with low
risk ranking do not have assets that can significantly impact the mission, are
thus not mission critical, and are thus relegated to a lesser priority for
further evaluation.

In this
approach mission critical assets are more rapidly identified with subsequent evaluations
more efficiently utilizing complementary tools saving time, staff resources,
and money.  We have also found that, due to the unique arrangement of the
assets within the system level and overall integration, this approach captures
risks that might otherwise be missed.

Base Case 1.  Envirex
Ground water remediation system

In mid 2004
a sequence of unusual, but not extraordinary, events led to an extended
shutdown of a key ground water remediation process consisting of extraction
wells, a fluidized bed activated media treatment process with filtration, and
internal re-use of the treated water.  The result of this was that the
owner was at considerable risk of consent decree violations.  Excellent
engineering, standard process reviews, HAZOPs, and an aggressive maintenance
program had not correctly identified risk. The need to find the true risks in
the system was paramount.

Response:

The owner
requested assistance in the evaluation of the overall process to identify the
as yet hidden risks and related potential issues in order to prevent future
similar and unforeseen occurrences.  The Uberlytics criticality analysis
approach and an early version of a software tool were brought in and applied in
a workshop environment where the owner's system experts, including engineers
and operators, were brought together with a criticality analysis expert
facilitator.

Inclusion of
100% of the overall process units in this functional area of the refinery, and
inclusion of pipes and valves as a separate group asset again proved
essential.  Successful discovery depended on the aforementioned and what
had previously not been done: leveraging the network system approach rather
than a discrete assets approach.

Results:

While the
owner's focus was primarily on preventing recurrence of the event that had
occurred, a full analysis of the system revealed several key aspects that led
to a more comprehensive understanding of the process and associated risks, as
well as providing specific improvement opportunities that would immensely
reduce risk with remarkable little effort and expense.  The networks
systems approach to criticality analysis pinpointed the issues behind the major
occurrence, and also found a number of other previously unidentified risks,
including one previously thought to be insignificant.  Commensurate simple
and cost effective solutions that immensely reduced the risk profile for the
entire process in all risk areas were identified.

Base
Case 2: Refinery boiler feed pretreatment RO system

Situation

A boiler
feed water pretreatment system was due for an expansion and had undergone
several design reviews, two HAZOP reviews, and several construction reviews.
However, given the importance of this system within the refinery operation, as
well as being a key part in the refinery overall water reuse initiative, the
refinery elected to commission an analysis on the plant boiler feed water
pretreatment system.  The decision to perform a criticality analysis was
also based, in part, on the success of the previous review
methodology.   However, since the system had also undergone some
annual refurbishments and, after 18 years of operation, was thought to be fully
?known', it was not expected that any previously unidentified issues would
surface.  This assumption proved to be false.

Response

As in the
previous example, the success of this analysis again hinged on the flexibility
of the analysis to include not only areas such as safety, environmental,
capacity, and up-time, but also commercial terms, liquidated damages, and
contract terms.  This proved to be a truly unique analysis in comparison
to the many previous ones that had been conducted on the process.  The results were reflective of more than just
a process view, showing the unique position of this process's risk profile
within the larger context of the client operation. 

The same
steps were conducted as in the previous case, except in here an asset registry
had previously been generated as part of a HAZOP review.  The database was
imported for the analysis.  Again, a team comprising various client
experts was assembled with a criticality analysis expert facilitator, and again
the unique approach proved essential.

Results

While the
analysis did clarify and further define the generally known critical areas
central to the overall mission, the analysis brought to the surface as yet
uncovered critical risks inherent to the system as well as a different than
expected risk ranking. One system was a particular surprise to the
investigating team as it could shut down the whole operation in a single shift,
and two other systems were elevated to a higher criticality ranking than
previously thought given the potential for overall system failure. The
inclusion of contractual and commercial evaluation parameters highlighted the
relationship between process and commercial risks that had previously gone
unnoticed.  This provided the opportunity to monetize those risks for a
more comprehensive business risk evaluation.

Conclusion

A
sophisticated yet efficient approach is required to identify all risks,
including hidden ones, in a cost effective way that also lends itself to
solution identification.  Conventional analysis and evaluation often fail
to identify some significant mission critical risks because they do not take
context into account.  The functional systems approach to criticality
analysis, FSCA, is a unique and proven approach that consistently meets and
exceeds that objective. This approach to criticality analysis reliably
identifies previously undiscovered system risks, means of mitigation, does so
in a more efficient way than conventional means, and delivers verifiable and
reproducible results.

Ignorance of
risk it is not absence of risk.