Dear Saltsafety,
If you gain grade C the non-conformities need to be closed on site,during a re-visit. During this visit only the non-conformities are verified and results are included in the original report.
For A and B grades the non-conformities are closed off-site, by sending evidence to the auditor/CB.
Perhaps your non-conformities were all documents to be changed and the auditor decided it is possible to do the verification off site. Perhaps the auditor was mistaking and just told you, what he/she tells after every audit.
4 days on site seems quite long to me too. As Tsmith7858 already said, the time on site depends on size of the site, number of workers, number of production lines, number of product groups, number of
HACCP-plans, etc.
I have seen the calculation model somewhere on this site.
Most CBs sent a questionnair to gain all this kind of information. Perhaps you (or someone of your organisation) filled in number f packing lines instead of proceslines, products instead of product groups and all workers instead of FTE. you also get reduction for working in shifts. e.g. if there are 30 persons working in a 3 shift system, there will be only 10 workers working during the audit.
Most important is the question: do you feel that the auditor did a good audit or do you feel that he/she was spending too much time drinking coffee and filling in checklists?
BtW is the reporting time included in this time on site? For your information: for an initial audit I need 2 days on site and 8 hours (=1 day) reporting.
The 6 months frequency is only as long as you have grade C. You will see that the next audit (over 6 months) the result will be B or A. Then you will have an annual frequency.