Good day
@ROOTS
It is not possible for "us" to know what controls your organization has or will put in place. The purpose of the
PFMEA is exactly that. i.e. What are the RISKS associated with "line down" and/or "cold start"?... Then identify what controls are or will be put in place to mitigate that risk. The abstract "gap" between the risks (and the associated severity) and the controls established, allow you to quantify an RPN or AP number (depending on the PFMEA type you are applying).
For example- if line down = customer line stoppage, then the risk may be significant.
Again, depending on the PFMEA type you are applying...the risk may result in a severity value of "8".
The final RPN or AP # can then be mitigated by the amount of controls in place . Therefore, if a 2 day safety stock is in place, a line stoppage in your facility may only cause an RPN value of 16 or an AP value of "L" (low). If, however, there is little/no control in place, then the risk to the customer may be reflect in an RPN value of 200 or an AP value of "M" (medium).
Hope this helps.
Be well.