1. If you were not having a proper document control system in place in past, you can reset revision numbers against a new issue number (i.e. Issue no.2 in your case). This will help to start fresh and maintain things properly. You'll have to write the details of revision in your document change history stating "new issue no. was raised and therefore all forms reset to 0 to upgrade to ISO9001:2015".
2. No problem even if you change revision numbers. Your old records will still remain valid. Revision in any form means from that date / as per your company policy, only the new format should be used.
So you mean, if ISO QMS updates, ISSUE NUMBER for my document will be set to issue# 3; rev. 00?
The answer to question 1 is no.
At the time of certification to ISO 9001, the auditor(s) will expect to see evidence of conformity to the standard for some period of time. If you show every document at Rev 0 it wouldn't show evidence that the document change process is working. Just because your system wasn't certified doesn't mean that the documents weren't controlled. I would recommend that all of your documents keep the revisions they are at currently.
That is what I was thinking too; auditors won't see evidence of controlling the document. I know there's no specific way to control document according to the standard and I was just preparing for possible query of the auditor.
Does adding ISSUE # + rev # will be insufficient? Document will be issue#2; rev. 00 from issue#1:rev5.
QUestion:
If I am going to retain REV5 on registration of the document, all previous rev(1 to 4) shall reflect the history right?
Same with if I am going to adopt ISSUE# plus REV #..
Big thanks to you guys