[7]     Calculate RPN

The RPN is the Risk Priority Number. The RPN gives us a relative risk ranking. The RPN is calculated by multiplying the three rankings together. Multiply the Severity ranking times the Occurrence ranking times the Detection ranking. For example,
Risk Priority Number (RPN) = (Severity) X (Occurrence) X (Detection)
Calculate the RPN for each failure mode and the corresponding effect. RPN will always be between 1 and 1000. The higher the RPN, the higher will be the relative risk. The RPN gives us an excellent way to prioritize focused improvement efforts.

[8]     Develop an action plan to address high RPN’s

Develop an action plan by which reduction in the RPN. The RPN can be reduced by lowering any of the three rankings (severity, occurrence, or detection) individually or in combination with one another.

[9]     Take action

The action plan outlines what steps are needed to implement the solution, who will do them, and when they will be completed. Responsibilities and target completion dates for specific actions to be taken are identified. All recommended actions must have a person assigned responsibility for completion of the action. There must be a completion date accompanying each recommended action. Unless the failure mode has been eliminated, severity should not change. Occurrence may or may not be lowered based upon the results of actions. Detection may or may not be lowered based upon the results of actions. If severity, occurrence or detection ratings are not improved, additional recommended actions must to be defined

[10]   Reevaluate the RPN after the actions are completed

This step is to confirm the action plan had the desired results by calculating the resulting RPN. To recalculate the RPN, reassess the severity, occurrence, and detection rankings for the failure modes after the action plan has been completed.

Tables 5.1.4 and 5.1.5 respectively show a typical worksheet and an example of failure mode and effect analysis for typical failures of engineering components.