One of the most important results from a FMEA is the assessment of failure mode and effect criticality. Criticality analysis determines the significance of individual failure modes and helps to prioritize them for corrective actions. To extend a FMEA to include criticality analysis, a method for measuring criticality must be defined. Qualitative approaches include Risk Priority Numbers (RPNs), risk levels, criticality matrices and Pareto rankings. Quantitative approaches include using failure rate data to compute failure mode criticality and item criticality.

When criticality is considered, the FMEA worksheet includes columns for indicating how often a failure mode is likely to occur. When failure rate data is not available, a qualitative approach to criticality is used. When failure rate data is available, a quantitative approach to criticality is generally used. Larger criticality values indicate more critical failure modes. In the FMEA report, criticality analysis worksheets should follow the failure mode and effects worksheets for the same indenture level.