When you change your process FMEA there are several documents which should be reviewed and, often, one or more will require changes. For example, if you add a potential problem to the FMEA for evaluation, after the evaluation it may or may not lead to an addition to the control plan. The same is true of the work instruction.
It should be noted that a change in a ‘severity’ on an FMEA can only be accomplished through a design change. Why is this so? This is because a change in the severity of the effect of a potential problem will not change by changing how often it occurs nor will it change by changing the probability of detection. These two issues do not change the effect(s) of the problem in any way, shape or form.
It should be evident that a change in detection on the process FMEA necessarily causes a change in the either the related work instruction (it may in fact cause the initiation of a new work instruction) and/or the control plan. In some cases another action may be initiated or changed in response to a change in detection. An example would be where a change in the process (driving the process flow diagram to change) is effected in response to an FMEA. The same is true with respect to a change in the occurrence. Changing the occurrence may, for example, change the sampling method, frequency, etc. on the control plan.
Effects of Changing the Process FMEA
Change in Detection
Change in Occurrence
Change in Severity
A change in the severity of the effect of a potential problem can only be effected through a design change.
When making a change to a document, it is important to consider the effects of that change on other documents. Typically the engineering change system in a company and/or corrective action system ensures these occur. But this is not always the case. Review your company engineering change procedure / system and see if it does so.