MOPO is required to be developed for the operations phase of the project as part of the COMAH process. The MOPO is a matrix, or set of matrices, that maps operational activities against foreseeable situations that, if or when they arise, could compromise safe operating limits. These situations are commonly identified from:
- The Threats and Escalation Factors identified as part of the Bow Tie assessments for Major Accident Hazards; and
- An assessment of other operations and activities that could contribute to the escalation of an incident (e.g. continuing with hot work when fire pumps are unavailable).
Threats and Escalation Factors along with other situations that could compromise safe operating limits are normally grouped under the following headings:
- Concurrent Operations, also referred to as SIMOPS (e.g. maintenance on critical elements and/or production and/or construction and/or drilling and/or diving);
- External influences (e.g. extreme weather, sea states, visibility); and
- Inactive safeguards (e.g. Emergency Shut Down (ESD), fire-fighting systems) not available or impaired.
The objective of a MOPO is to maintain an acceptable level of risk for the operations. The matrices shall identify and differentiate between ‘stop’ conditions (i.e. operation not permitted) and what are ‘proceed with caution’ conditions, (i.e. continue but recognize that there is an increased risk and/or provide additional controls). Traffic lighting (i.e. red for “stop” and amber for “proceed with caution”) is a useful tool to highlight the different conditions and should be adopted.
The MOPO shall be for permitted operations and not for prohibited operations, since the latter may lead to the possible interpretation that anything not specifically prohibited is allowed.
MOPO shall be developed in a workshop for the projects. For modification projects where no changes are seen in operating philosophy, MOPO can be retained from the existing facilities COMAH report. Where such information is not available, MOPO shall be developed.