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Haward Technology Middle East
PIONEERS IN TECHNOLOGY TRANSFER
API-580/581: Introduction to Risk
Based Inspection Methodologies and
Practices in Refineries, Gas, Oil &
Petrochemical Facilities (RBI)

2. API-580/581: Introduction to Risk Based Inspection
Methodologies and Practices in Refineries, Gas, Oil &
Petrochemical Facilities (RBI)
Haward Technology Middle East 2
Section 1
Section 1
Introduction to Risk-Based Inspection

3. API-580/581: Introduction to Risk Based Inspection
Methodologies and Practices in Refineries, Gas, Oil &
Petrochemical Facilities (RBI)
Haward Technology Middle East 3
Section 1
Introduction to Risk-Based Inspection

4. API-580/581: Introduction to Risk Based Inspection
Methodologies and Practices in Refineries, Gas, Oil &
Petrochemical Facilities (RBI)
Haward Technology Middle East 4
Section 1
What is Risk-Based Inspection?
 Strategic, systematic process for identifying and
managing risk and its associated costs
 Integrated, data-based methodology
 Factors the level of risk into a decision-making process
for inspection planning and execution
 Includes likelihood of failure (LOF) and consequence of
failure (COF)
 Includes both qualitative and quantitative analysis
 Prioritizes relative and/or absolute risk
 Identifies areas requiring risk mitigation

5. API-580/581: Introduction to Risk Based Inspection
Methodologies and Practices in Refineries, Gas, Oil &
Petrochemical Facilities (RBI)
Haward Technology Middle East 5
Section 1
Approaches to Risk-Based Inspection
 There are many different types of RBI methodology
• API Recommended Practice 580
‐ Focus of this Course
• ASME Inspection Planning Standard
‐ Major focus is on nuclear and fossil power
generation
• Proprietary commercial methods
• Owner-User methods

6. API-580/581: Introduction to Risk Based Inspection
Methodologies and Practices in Refineries, Gas, Oil &
Petrochemical Facilities (RBI)
Haward Technology Middle East 6
Section 1
Scope of Risk-Based Inspection
 RBI as developed by API under RP 580 is targeted at
the hydrocarbon industry, including:
• Petroleum Refining
• Oil & Gas
• Chemicals
• Petrochemicals
However, RBI principles will work in any industry exposed
to risk.

7. API-580/581: Introduction to Risk Based Inspection
Methodologies and Practices in Refineries, Gas, Oil &
Petrochemical Facilities (RBI)
Haward Technology Middle East 7
Section 1
Scope of Equipment
 Covered Equipment
• Pressure Vessels
• Process Piping
• Heat Exchangers
• Heaters and Boilers
• Storage Tanks
• Rotating Equipment
‐ Pressure boundary
• Pressure Relief Devices
 Excluded Equipment
• Instrumentation
• Control Systems
• Electrical Systems
• Structural Systems
Machinery Components

8. API-580/581: Introduction to Risk Based Inspection
Methodologies and Practices in Refineries, Gas, Oil &
Petrochemical Facilities (RBI)
Haward Technology Middle East 8
Section 1
Linkage to Other Concepts

9. API-580/581: Introduction to Risk Based Inspection
Methodologies and Practices in Refineries, Gas, Oil &
Petrochemical Facilities (RBI)
Haward Technology Middle East 9
Section 1
Process Hazard Analysis (PHA) Linkage
 PHA + RBI = Total Process and Mechanical and
Integrity Hazards Analysis Associated
with Operating Plants

10. API-580/581: Introduction to Risk Based Inspection
Methodologies and Practices in Refineries, Gas, Oil &
Petrochemical Facilities (RBI)
Haward Technology Middle East 10
Section 1
Reliability Centered Maintenance (RCM)
Linkage
 RCM + RBI = Total Reliability and Pressure Integrity
Analysis for Functional Breakdown and
Leak/Rupture

11. API-580/581: Introduction to Risk Based Inspection
Methodologies and Practices in Refineries, Gas, Oil &
Petrochemical Facilities (RBI)
Haward Technology Middle East 11
Section 1
Some Definitions
Consequence
Outcome from an event. There may be one or more
consequences from an event. Consequences may range
from positive to negative. However, consequences are
always negative for safety aspects. Consequences may be
expressed qualitatively or quantitatively.

12. API-580/581: Introduction to Risk Based Inspection
Methodologies and Practices in Refineries, Gas, Oil &
Petrochemical Facilities (RBI)
Haward Technology Middle East 12
Section 1
Damage Tolerance and Deterioration
Damage Tolerance
The amount of deterioration that a component can
withstand without failing.
Deterioration
The reduction in the ability of a component to provide its
intended purpose of containment of fluids. This is caused
by various deterioration mechanisms (e.g. thinning,
cracking, mechanical). Damage or degradation may be
used in place of deterioration.

13. API-580/581: Introduction to Risk Based Inspection
Methodologies and Practices in Refineries, Gas, Oil &
Petrochemical Facilities (RBI)
Haward Technology Middle East 13
Section 1
Event and Event Tree
Event
Occurrence of a particular set of circumstances. The
event may be certain, uncertain, single or multiple. The
probability associated with the event is estimated for a
given period of time.
Event Tree
A tool that organizes potential accidents in a logical
manner. The event tree begins with identification of
potential initiating events. Subsequent possible resulting
events are then displayed as the second level and so on
until pathways or scenarios from the initiating events to
potential outcomes are built up.

14. API-580/581: Introduction to Risk Based Inspection
Methodologies and Practices in Refineries, Gas, Oil &
Petrochemical Facilities (RBI)
Haward Technology Middle East 14
Section 1
External Event
External events are usually beyond the direct or indirect
control of persons employed at or by the facility. Events
resulting from forces of nature, acts of Allah or sabotage,
or neighboring events, fires or explosions, hazardous
releases, electrical power failures, climatic catastrophes,
earthquakes, and intrusions.

15. API-580/581: Introduction to Risk Based Inspection
Methodologies and Practices in Refineries, Gas, Oil &
Petrochemical Facilities (RBI)
Haward Technology Middle East 15
Section 1
Failure
Termination of the ability of a system, structure, or
component to perform its required function of
containment of fluid (i.e. loss of containment). Failures
may be unannounced and undetected until the next
inspection (unannounced failure), or they may be
announced and detected by any number of methods at
the instance of occurrence (announced failure).

16. API-580/581: Introduction to Risk Based Inspection
Methodologies and Practices in Refineries, Gas, Oil &
Petrochemical Facilities (RBI)
Haward Technology Middle East 16
Section 1
Failure Mode
The manner of failure. For Risk- Based Inspection, the
failure of concern is loss of containment of pressurized
equipment items. Examples of failure modes are small
hole, crack, and rupture.

17. API-580/581: Introduction to Risk Based Inspection
Methodologies and Practices in Refineries, Gas, Oil &
Petrochemical Facilities (RBI)
Haward Technology Middle East 17
Section 1
Source and Hazard
Source
Thing or activity with a potential for consequence.
Source in a safety context is a hazard.
Hazard
A physical condition or a release of a hazardous material
that can result in human injury or death, loss or damage,
or environmental degradation. Hazard is the source of
harm. Components that are used to transport, store, or
process a hazardous material are a source of hazard.

18. API-580/581: Introduction to Risk Based Inspection
Methodologies and Practices in Refineries, Gas, Oil &
Petrochemical Facilities (RBI)
Haward Technology Middle East 18
Section 1
Hazard and Operability Study
Hazard and Operability (HAZOP) Study
A form of failure modes and effects analysis, which uses
systematic techniques to identify hazards and operability
issues. Identifying unforeseen design, process, or
operational hazards.

19. API-580/581: Introduction to Risk Based Inspection
Methodologies and Practices in Refineries, Gas, Oil &
Petrochemical Facilities (RBI)
Haward Technology Middle East 19
Section 1
Hazard and Operability Study
The basic objectives are:
 To produce a full description of the facility or process,
including the intended design conditions
 To systematically review every part to discover how
deviations from the intention of the design can occur
 To decide whether deviations can lead to hazards or
operability issues
 To assess effectiveness of safeguards

20. API-580/581: Introduction to Risk Based Inspection
Methodologies and Practices in Refineries, Gas, Oil &
Petrochemical Facilities (RBI)
Haward Technology Middle East 20
Section 1
Likelihood and Probability
Extent to which an event is likely to occur within a time
frame. Probability is “a real number from o to 1 attached
to a random event”. Probability is related to long-run
relative frequency or degree of belief in an occurrence.
Frequency rather than probability is used. Degrees of
belief is chosen as classes or ranks.
 “Rare/unlikely/moderate/likely/al most certain” or
“incredible/improbable/remote/occasional/probable/
frequent”.

21. API-580/581: Introduction to Risk Based Inspection
Methodologies and Practices in Refineries, Gas, Oil &
Petrochemical Facilities (RBI)
Haward Technology Middle East 21
Section 1
Qualitative Risk Analysis
Qualitative Risk Analysis (Assessment)
Method that uses engineering judgment and experience
as the basis for analysis of probabilities and
consequences of failure.
1. Results of qualitative risk analyses are dependent on
the background and expertise of the analysts and the
objectives of the analysis.

22. API-580/581: Introduction to Risk Based Inspection
Methodologies and Practices in Refineries, Gas, Oil &
Petrochemical Facilities (RBI)
Haward Technology Middle East 22
Section 1
Qualitative Risk Analysis
Qualitative Risk Analysis (Assessment)
2. Failure Modes, Effects, and Criticality Analysis
(FMECA) and HAZOPs are examples of qualitative risk
analysis techniques that become quantitative risk
analysis methods when consequence and failure
probability values are estimated along with the
respective descriptive input.

23. API-580/581: Introduction to Risk Based Inspection
Methodologies and Practices in Refineries, Gas, Oil &
Petrochemical Facilities (RBI)
Haward Technology Middle East 23
Section 1
Qualitative Risk Analysis
Qualitative Risk Analysis (Assessment)
3. Identifies and delineates the combinations of events
that, if they occur, will lead to a severe accident
(e.g. major explosion) or any other undesired event.
4. Estimates the frequency of occurrence for each
combination and estimates the consequences.

24. API-580/581: Introduction to Risk Based Inspection
Methodologies and Practices in Refineries, Gas, Oil &
Petrochemical Facilities (RBI)
Haward Technology Middle East 24
Section 1
Qualitative Risk Analysis
Qualitative Risk Analysis (Assessment)
5. Quantitative risk analysis integrates into a uniform
methodology the relevant information about:
• Design, operating practices and history
• Reliability
• Human actions
• Physical progression of accidents
• Potential health and environmental effects, as
realistically as possible

25. API-580/581: Introduction to Risk Based Inspection
Methodologies and Practices in Refineries, Gas, Oil &
Petrochemical Facilities (RBI)
Haward Technology Middle East 25
Section 1
Qualitative Risk Analysis
Qualitative Risk Analysis (Assessment)
6. Quantitative risk analysis uses logic models depicting
combinations of events that could result in severe
accidents and physical models depicting the
progression of accidents and the transport of a
hazardous material to the environment.
7. The models are evaluated probabilistically to provide
both qualitative and quantitative insights about the
level of risk and to identify the design, site, or
operational characteristics that are the most
important to risk.

26. API-580/581: Introduction to Risk Based Inspection
Methodologies and Practices in Refineries, Gas, Oil &
Petrochemical Facilities (RBI)
Haward Technology Middle East 26
Section 1
Qualitative Risk Analysis
Qualitative Risk Analysis (Assessment)
8. Quantitative risk analysis logic models generally
consist of event trees and fault trees
9. Event trees delineate initiating events and
combinations of system successes and failures
10.Fault trees depict ways in which the system failures
represented in the event trees can occur
11.These models are analyzed to estimate the frequency
of each accident sequence

27. API-580/581: Introduction to Risk Based Inspection
Methodologies and Practices in Refineries, Gas, Oil &
Petrochemical Facilities (RBI)
Haward Technology Middle East 27
Section 1
Relative, Absolute, and Residual Risk
Risk: Combination of probability of an event and its
consequence. In some cases, risk is a deviation from the
expected. When probability and consequence are
expressed numerically, risk is the product.
Relative Risk: The comparative risk of a facility, process
unit, system, or equipment to other facilities, process
units, systems, or equipment, respectively.
Absolute Risk: An ideal description of quantification risk.
Residual Risk: The risk remaining after mitigation.

28. API-580/581: Introduction to Risk Based Inspection
Methodologies and Practices in Refineries, Gas, Oil &
Petrochemical Facilities (RBI)
Haward Technology Middle East 28
Section 1
Risk
Risk Analysis: Systematic use of information to identify
sources and to estimate the risk.
• Risk analysis provides a basis for risk evaluation and
risk acceptance. Information can include historical
data, analysis, informed opinions and concerns of
stakeholders.
Risk Assessment: Overall process of risk analysis and risk
evaluation.
Risk Acceptance: A decision to accept a risk. Risk
acceptance depends on risk criteria.

29. API-580/581: Introduction to Risk Based Inspection
Methodologies and Practices in Refineries, Gas, Oil &
Petrochemical Facilities (RBI)
Haward Technology Middle East 29
Section 1
Risk Criteria and Identification
Risk Criteria: Terms of reference by which the
significance of risk is assessed. Risk criteria may include
associated cost and benefits, legal and statutory
requirements, socio-economic and environmental
aspects, concerns of stakeholders, priorities and other
inputs to the assessment.
Risk Identification: Process to find, list, and characterize
elements of risk. Elements may include; source, event,
consequence, probability. Risk identification may also
identify stakeholder concerns.

30. API-580/581: Introduction to Risk Based Inspection
Methodologies and Practices in Refineries, Gas, Oil &
Petrochemical Facilities (RBI)
Haward Technology Middle East 30
Section 1
Risk Estimation and Evaluation
Risk Estimation: Process used to assign values to the
probability and consequence of a risk. Risk estimation
may consider cost, benefits, stakeholder concerns and
other variables, as appropriate for risk evaluation.
Risk Evaluation: Process used to compare the estimated
risk against given risk criteria to determine the
significance of the risk. Risk evaluation may be used to
assist in the acceptance or treatment decision concerns.

31. API-580/581: Introduction to Risk Based Inspection
Methodologies and Practices in Refineries, Gas, Oil &
Petrochemical Facilities (RBI)
Haward Technology Middle East 31
Section 1
Risk Management, Mitigation, and Reduction
Risk Management: Coordinated activities to direct and
control risk. Typically includes risk assessment, risk
mitigation, risk acceptance and risk communication.
Risk Mitigation: Process of selection and implementation
of measures to modify risk. The term is sometimes used
for the measures themselves.
Risk Reduction: Actions taken to lessen the probability,
negative consequences, or both associated with a
particular risk.

32. API-580/581: Introduction to Risk Based Inspection
Methodologies and Practices in Refineries, Gas, Oil &
Petrochemical Facilities (RBI)
Haward Technology Middle East 32
Section 1
Risk Avoidance and Control
Risk Avoidance: Decision not to become involved in, or
action to withdraw from a risk situation.
The decision may be taken based on the result of risk
evaluation.
Risk Control: Actions implementing risk management
decisions. Risk control may involve monitoring, re-
evaluation, acceptance and compliance with decisions.

33. API-580/581: Introduction to Risk Based Inspection
Methodologies and Practices in Refineries, Gas, Oil &
Petrochemical Facilities (RBI)
Haward Technology Middle East 33
Section 1
Risk-Based Inspection
Risk-Based Inspection
A risk assessment and management process that is
focused on loss of containment of pressurized equipment
in processing facilities, due to material deterioration.
• These risks are managed primarily through equipment
inspection.

34. API-580/581: Introduction to Risk Based Inspection
Methodologies and Practices in Refineries, Gas, Oil &
Petrochemical Facilities (RBI)
Haward Technology Middle East 34
Section 1
End of This
Section