Asset Threats and Consequence of Failure

This section attempts to outline some of the steps involved when establishing an Integrity Management System including Trend Analysis and RBI. This high-level process is generic and applicable to all static equipment classes, e.g. structures, (topside/underwater), process, pipelines, subsea equipment and control systems.

List All Failure Threats Applicable to Each Asset

  • Each asset has a number of threats to its integrity. Some examples are: dropped objects, internal and external corrosion, free-spanning subsea pipelines and many more.
  • The list of threats will differ for each asset. For example, internal corrosion might apply to a riser but not to an anchor chain.
  • Often failure threats are listed in existing documents, such as safety cases, design documents and maintenance manuals.


Probability of Failure Levels

  • PoF levels are defined for each Asset Failure/Threat combination.
  • Initial PoF levels may be defined in existing Safety Case documentation.
    Below is an example:

Probability Level
Guideline

 
Assumed mean time between failures (MTBF) for non-trended threats
A
 Never heard of in industry
16 years
B
 Incident has occurred in oil industry
8 years
C
 Incident has occurred in Region
4 years
D
 Incident happens several times per year in Region (+) and could occur in the company
2 years
E
 Incident has already happened or could occur several times per year in the company
1 year
Consequence of Failure Levels

  • CoF levels are defined for each Asset.
  • Often CoF levels are defined in existing client HSE documents.
    Below is an example:


Consequence
Level
People
Assets
Total Cost of incident in USD
Environment Reputation
0
 No Health Effect/Injury No damage, zero cost No Effect No impact
1
 Slight Health Effect/Injury Slight damage $10,000 Slight Effect Slight impact
2
 Minor Health Effect/Injury Minor damage $100,000 Minor Effect Limited impact
3
 Major Health Effect/Injury Localised damage
$1 million 		Localised Effect Considerable impact
4
 PTD or 1 to 3. Single Fatality Major damage
$10 million		 Major Effect National impact
5
 Multiple Fatalities Extensive damage
$10 million 		Massive Effect International impact
Overall CoF level is the highest of the four CoF elements listed above