As the design-responsible agency, your job is now easier (and much more difficult at the same time).
Your design team needs to determine what is and is not a critical or significant characteristic. Evaluation and determination should follow some fairly simple guidelines.
EXAMPLE (These are not official guidelines, these are my own PERSONAL guidelines which I have used in the past, and which have been accepted as satisfactory by customers and auditors)
Which failure(s) will cause, WITHOUT WARNING, injury or death to vehicle occupants? (I am presuming that you are supplying automotive). Those would be CC's, with a SEV of 10.
Which failure(s) will cause, WITH WARNING, injury or death to occupants, or will cause the assembly to fail to properly function (i.e. unable to release seat belt buckle, unable to unlock doors, etc), resulting in potential of injury or death to occupants. These would be CC's, with a SEV of 9.
SC's would involve failure to function of the assembly which would NOT result in injury or death (i.e. ignition fails to spark, lights don't turn on) but which DO result in a total failure of the system. This would be a SEV 10
Failures which involve a MAJOR inconvenience to the occupant (seat motor does not function consistently, cannot fine-adjust seat position) would be a SEV 9.
Remember, the
FMEA manual only SUGGESTS the scoring system to use, it is not mandatory. You can develop your own company, process, or part-specific scoring system, based on your knowledge of your systems. As long as it is consistent, and your customer accepts it, then it's fine.