As we started to look at on the previous page, it is evident that the process flow diagram be ‘completed’ early. This is because it serves to identify all processes involved from which internal critical (special, whatever) characteristics are derived. I have only seen a couple of companies which got through a QS audit with NO internal critical / special characteristic.
The above illustration shows the internal links in these documents which key each to the other. Note that the design FMEA does not have an internal link to the process FMEA because the design FMEA addresses intended use as opposed th the process FMEA which addresses processes.
Note that on this example the PFMEA, the control plan and the process flow diagram have ‘links’ (in this example the Operation Number). Later in this presentation we will address situations where these documents are looked at as ‘elements’ as opposed to discrete documents. Looking at each of these as discrete documents is the classical way of representing the requirements, however in many cases, such as companies which use Ford’s DCE methodology (Dynamic Control Plan), two or more ‘elements’ may be in one document. From this it is obvious that there is no intra-document linkage as illustrated above. Meeting the intent is that separate documents be linked.
Document Links
Process Flow Chart
Operation Number
Product/Process Characteristic
Incoming Sources of Variation
(Variation Class)
Work Instruction
Operation Number
PFMEA
Operation Number
Control Plan
Operation Number
Product/Process Characteristic
Incoming Sources of Variation
(Variation Class)
The APQP manual cites these links. In some companies, these are not discrete documents.
