Page 34 - Pipeline Risk Management Manual Ideas, Techniques, and Resources

Conceptualizing a risk assessment approach 1/13
capture much detailed information because they already assessment for its intended use but rather are deviations from other
have it available; others will want to get started with a very possible risk assessment approaches. These deviations include the
simple framework. However, by using the same overall risk following:
assessment framework, results can still be compared: from Relative risks only: Absolute risk estimations are not included
very detailed approaches to overview approaches. because of their highly uncertain nature and potential for misunder-
Resource allocation (or reallocation) is normally the most standing. Due to the lack of historical pipeline failure data for various
failure mechanisms, and incomplete incident data for a multitude of
effective way to practice risk management. Costs must there- integrity threats and release impacts, a statistically valid database is
fore play a role in risk management. Because resources are not thought to be available to adequately quantify the probability of
finite, the optimum allocation of those scarce resources is a failure (e.g., failureskm-year), the monetized consequences of a
sought. failure (e.g., dollars/failure), or the combined total risk of a failure
The methodology should “get smarter” as we ourselves (e.g., dollarskm-year) on apipeline-specific basis.
learn. As more information becomes available or as new Certuin consequences: The focus ofthis assessment is on risks to pub-
techniques come into favor, the methodology should be flex- lic safety and the environment. Other consequences such as cost of
business interruption and risks to company employees are not specifi-
ible enough to incorporate the new knowledge, whether that cally quantified. However, most other consequences are thought to be
new knowledge is in the form of hard statistics, new beliefs, proportional to the public safety and environmental threats so the
or better ways to combine risk variables. results will generally apply to most consequences.
Methodology should be robust enough to apply to small as Abnormal conditions: This risk assessment shows the relative risks
well as large facilities, allowing an operator to divide a large along the pipeline during its operation. The focus is on abnormal con-
facility into subsets for comparisons within a system as well ditions, specifically the unintentional releases of product. Risks from
as between systems. normal operations include those from employee vehicle and water-
Methodology should have the ability to distinguish between craft operation; other equipment operation; use of tools and cleaning
and maintenance fluids; and other aspects that are considered to add
products handled by including critical fluid properties, normal and/or negligible additional risks to the public. Potential con-
which are derived from easy-to-obtain product information. struction risks associated with new pipeline installations are also not
Methodology should be easy to set up on paper or in an considered.
electronic spreadsheet and also easy to migrate to more Insensitivity to length: The pipeline risk scores represent the relative
robust database software environments for more rigorous level of risk that each point along the pipeline presents to its surround-
applications. ings. is the scores are insensitive to length. If two pipeline segments,
Methodology documentation should provide the user with 100 and 2600 ft, respectively, have the same risk score, then each
simple steps, but also provide the background (sometimes point along the 100-8 segment presents the same risk as does each
point along the 2600-ft length. Of course, the 2600-ft length presents
complex) underlying the simple steps. more overall risk than does the 100-A length, because it has many
Administrative elements of a risk management program are more risk-producing points.
necessary to ensure continuity and consistency of the effort. Note: With regard to length sensitivity, a cumulative risk calculation
adds the length aspect so that a 100-A length ofpipeline with one risk
Note that ifthe reader concurs with these beliefs, the bulleted score can be compared against a 2600-A length with a different
items above can form the foundation for a model design or risk score.
an inquiry to service providers who offer pipeline risk Use of judgment: As with any risk assessment methodology, some
subjectivity in the form of expert opinion and engineering judgments
assessmenurisk management products and services. are required when “hard” data provide incomplete knowledge. This is
a limitation of this assessment only in that it might he considered a
Scope and limitations limitation of all risk assessments. See also discussions in this section
dealing with uncertainty.
Having made some preliminary decisions regarding the risk
management’s program scope and content, some documenta- Related to these statements is a list of assumptions that
tion should be established. This should become a part of the might underlie a risk assessment. An example of documented
overall control document set as discussed in Chapter 15. assumptions that overlap the above list to some extent is
Because a pipeline risk assessment cannot be all things at provided elsewhere.
once, a statement of the program’s scope and limitations is usu-
ally appropriate. The scope should address exactly what por-
tions of the pipeline system are included and what risks are Formal vs. informal risk management
being evaluated. The following statements are examples of
scope and limitation statements that are common to many Although formal pipeline risk management is growing in popu-
relative risk assessments. larity among pipeline operators and is increasingly mandated
by government regulations, it is important to note that risk man-
This risk assessment covers all pipe and appurtenances that are a part agement has always been practiced by these pipeline operators.
of the ABC Pipeline Company from Station Alpha to Station Beta as Every time a decision is made to spend resources in a certain
shown on system maps. way, a risk management decision has been made. This informal
This assessment is complete and comprehensive in terms ofits abil- approach to risk management has served us well, as evidenced
ity to capture all pertinent information and provide meaningful analy- by the very good safety record of pipelines versus other modes
ses of current risks. Since the objective of the risk assessment is to
provide a useful tool to support decision making, and since it is of transportation. An informal approach to risk management
intended to continuously evolve as new information is received, some can have the further advantages of being simple, easy to
aspects of academician-type risk assessment methodologies are inten- comprehend and to communicate, and the product of expert
tionally omitted. These are not thought to produce limitations in the engineering consensus built on solid experience.