Criticality helps us to determine the level of attention to focus on specific things, given most of our attention should be given to our most critical assets and scenarios. The remaining effort must be spread across everything else. There should only be ONE way to assess criticality in your organization (i.e., Process Safety Critical vs. Asset Critical).
Many organizations use a risk matrix for qualitative risk, but we often see different risk matrices applied across different types of criticality assessments (safety, environmental compliance, risk-based inspection, equipment, etc.). Qualitative risk is inherently subjective, meaning your interpretation and mine of risk may be different, even when looking at the same risk criteria.
Having different views and often different scales of risk results in:
- Too many things being important, meaning that in reality, nothing is actually important / deserving of additional attention
- Infighting over budgets, resources and project priorities
Here is an example risk matrix:
Risks must be quantified in terms of probability or likelihood and also by severity (or consequence) should the event/failure/scenario occur. To consistently quantify risk across different risk types we need numbers for each likelihood and severity. For Example:
Likelihood (where each category should be an order of magnitude greater than the one below it):
Severity
Some key ideas to think about:
- Usually, one category of risk is the main driver, although it can be two or more.
- The highest risk by category determines the OVERALL
- Often, the same activities/actions are taken to remove or mitigate the risk regardless of which category is driving the risk.
- The severity of the event usually does not change --> things move left and right on the risk matrix over time, but seldom move up or down.
- Loss of redundancy can impact risk.
- Over time, individual risks move from left to right until risks are “reset” through some activity (repair, re-assessment, review, inspection, etc.).
From a business standpoint, we want to operate as much as possible in the lower left corner of the risk matrix. While individual risks are constantly moving, we want to keep our overall risk level as constant as feasible:
Examples of how criticality can be used include:
- Reliability-Centered Maintenance (RCM), Failure Modes and Effects (FMEA), strategy templates, and Preventive Maintenance (PM) optimization for rotation, electrical, and other mechanical equipment
- Risk-Based Inspection (RBI) studies for fixed or static equipment
- Layers of Protection Analysis (LOPA) for instrumentation, safety, and control loops
- Spares optimization to drive stocking levels
- Work management and maintenance backlog priorities
Does your software support your process and enable dynamic criticality as changes occur vs. using a spreadsheet or the limited capabilities within most Computerized Maintenance Management System (CMMS) software to track criticality results? Can you trace the execution of your critical tasks through to completion?
The OESuite® Asset Analysis module from OS can perform a top-down analysis of Criticality by Unit, then System, then Asset, with downward inheritance, and the ability to adjust individual items as appropriate.