Hello,
I apologize for the length of this answer in advance - however this has been a pet peeve of mine for many years.
The AIAG has never stepped up to the question of what format for a PROCESS Flow diagram is even reccomended - older versions of the AIAG books did try and give several different examples.
In the AIAG 4th edition of the PPAP book page ii shows a PPAP Process Flow Diagram in a pictorial format - and please remember the AIAG is a suggested set of guidlines to follow and in some cases are fully accepted by our customers and in other cases they are less interested in having a specific format.
The example that you have referenced has been the mainstay for many years (1967 in my memory) with some minor changes here and there. But most companies have strayed away form this format in favor of the pictorial (Like the one in the AIAG book) and some have even gone to a floor plan type visual - normally because the purpose of the document has been lost.
Here are some of the reasons why your example is the one I would prefer if you were my supplier.
The original Flow Diagrams were meant to be developed during the early stages of the Process Development and were intended to be the spring boards for the
PFMEA and eventually the Control Plan.
Here is some of that reasoning.
The older format that you have is in a linear/Pictorial format (I.E.) - over 70% of the population of this planet thinks in a Linear Fashion, they are known as Linear Thinkers. Around 20% of the population think in a non-linear fashion - Known as Non-Linear thinkers. the rest of the population just don't think I guess. this allows the largest portion of the population pick the document up and have a begining understanding right away.
The expectation is that you would capture every Step and every operation in the process including incoming receiving, Material moves, et.
A step is normally everything in the process and some steps are also operations.
Example: Material movement is just a STEP.
Example: Any step that also changes the material/product in any way (Grinding, drilling, Chemical changes and so on).
Once you have captured every step and every step/operation you can look at the Process Characteristics and Product Characteristics and add them to the Flow Diagram at the appropriate line item.
This may look like a lot of work - it shouldn't be - even a relatively complicated process should not take very long or you may be over complicating the Flow Diagram - normally you only put very basic information - for instance you put Diameter not Diameter 30mm +/- .10mm. or Length - not length 1.5mm +/- .10
When the Flow Diagram is filled out in this manner - it becomes very easy to review each line item and give it a risk level (you can make up your own) Example: 1 = Low risk
2 = Medium Risk 3 = High Risk
This is done to reduce the development time of the PFMEA and virtually build the Control Plan.
Every Step and Step/Operation is directly tranferable to the PFMEA (this is known as linking the documents and has nothing to do with the computer age) afterwhich some Steps and Operations are directly transferable to the Control Plan Note: not all steps would be transfered so there would be missing numbers for some steps - for instance Material movement steps are not typically put in the control plans.
One of the other considerations is if you move an operation into a different location within the four walls of your plant - normally you only have to notifiy your customer of the move - your Flow Diagram remains the same - using a Pictorial or Floor Plan format may require more attention.
I do not believe the AIAG has a blessed version, your customer may a prefered verson - However, if you can defend your reasoning for one format over another they'll normally buy it.
Again,
Sorry for the length, but wanted you to get a flavor of the purpose and importance of the Flow Diagram so that you might have some reasoning for your choice.
If you intend to use the older document - I can upload an example on Monday.
Best Regards
Tom