When to exicute/complete the Software Validation

I just stumbled across this forum and it looks like a pretty good resource.

I was having a conversation with some colleges of when a software validation needs to be completed in line with the process or equipment validation. One argument was that a SV is required to be completed at the conclusion to the Process/Equipment IQ, prior to the start of the OQ.

I see some problems with that line of thinking in that there could be some requirements that are not able to be tested until at lease the Process/Equipment OQ is completed.

I have other ideas but thought it would be nice to hear some other stances with this question.

Thanks for your time