Planning the RBI Assessment
Start with the plan, not the data
A defensible RBI assessment begins with a written plan that establishes, in order: the objective (what decision the study must support), the scope and boundaries (which units, systems, equipment types, and which exclusions), the methodology (qualitative, semi-quantitative, or quantitative), the team, the data requirements, the risk acceptance criteria, the schedule and resources, and the documentation and review requirements.
Scope decisions that matter
The scope must be explicit about equipment boundaries - for example, whether piping circuits, relief systems, utility systems, and instrumented protective functions are included. Items that carry large consequence but little perceived deterioration (flare systems, storage, utilities) are often wrongly excluded. If risk targets are used to focus effort, they should be defined by the owner/user before analysis, not adjusted afterwards.
Choosing the method
The method must match the decision and the data available. Screening-level qualitative methods are fine for coarse prioritization across many assets; semi-quantitative methods suit most operating plants; fully quantitative methods are used where the consequences are severe or the decision is expensive. Selecting the method after seeing the results is a serious credibility failure.
Traps in questions
- Confusing the plan with the assessment: the plan sets scope and criteria, the assessment produces the risk values.
- Assuming data collection comes first; scope and criteria must be fixed so you know what data to collect.
- Ignoring that the owner/user, not the analyst, approves risk criteria and the assessment plan.
Rule of thumb
If you cannot state, in one sentence, the decision the RBI assessment will support, the plan is not finished.