I agree that they are different in some ways, however they are as alike as they are different. Early on, as I understand it, ISIR (also called ISR and several other acronymns) was just a layout inspection.
I first ran into ISIR (Initial Sample Inspection Report) requirements during the military manufacturing phase of my life. What comprised an ISIR in the 1970's and 1980's was dependent upon the specific contract and the specific customer. Sometimes it was just a layout. Sometimes, as in the automotive PPAP, it included inspection and test data and/or run-off data and/or sample parts, etc.
-> I've been asked to do a contract at a firm which require
-> PPAP's being finished, I've actually performed the PPAP
-> process so at this stage would not know were to begin,
-> you say they are similar to ISIR that's fine and I have
-> an understanding of the FMEA process (not brilliant but
-> okay!) am I worrying to much about nothing or will all be
-> okay and fit into place. My boss has every confidence in
-> sending me into the big wide world - I'm a contracted
-> Quality Engineer who recently completed a 12 month
-> contract as a Quality Systems Engineer (ISO 9000) NOT
-> doing FMEA's though just 9000 stuff.
Well, PPAP is what your customer has defined for you. The impotant part is you go through the APQP process as dictated for a part or product. PPAP is the submission of the results - runoff data, layout, sample parts, etc. But like the way I learned military ISIR, not every APQP process is the same. I once had a customer who produced about 5 specialty parts for GM every year. Their APQP process (and thus their PPAP) was quite different than that of a customer which supplied over 1M struts a year to Ford.
Each APQP is different and since PPAP is simply submission of data from the APQP process, etc., each PPAP is also different. An example is that a process FMEA and control plan is required to be produced during the APQP process. PPAP is where you submit the FMEA.