The failure rate (FR) for a mode indicates the number of occurrences of this mode over some time period. The mode FR is calculated when FMEA results are calculated. The mode FR uses the failure rate multiplier when it is shown. If Mode Percentage is blank, a value of 100% is assumed. If the sum of failure mode percentages for an item is not equal to 100%, a warning is shown in the FMEA Warnings window. This window opens when you verify the configuration and setup of your FMEA. For more information, see Verifying FMEA Data.

The equation for calculating mode FR is:

For example, assume that you have two modes, one responsible for 80% of the failures and one responsible for 20% of the failures. You would enter 80 and 20 as their respective mode percentages. To obtain the mode failure rate, the mode percentage is divided by 100. This value is then multiplied by the item FR.