Isolation percentage is the probability that the failure mode can be attributed to a specific part. Isolation percentage is calculated for parts and assemblies. While the range should be from 0 to 100, this is not enforced. You can insert Isolation Percentage in the FMEA Tree Items table. The assembly FR is the FR for the item in the FMEA Tree. The assembly FR is zero for a non-linked item in a process or functional FMEA.

The equation for calculating isolation percentage is: