where does checking for precondition of audit start in the tendering process?

Hi fellow audit gods,

A fellow greenhorn auditor have a question for you all, when does checking for audit precondition begin? I understand that auditor should only accept audit engagement when precondition for audit are met. However, I would like to know when precisely does it start in reference to the time frame for audit tendering process provided from KPMG’s website.

https://home.kpmg/content/dam/kpmg/ie/pdf/2017/10/17-how-to-conduct-an-audit-tender.docx

Thank you!
Fellow greenhorn signing off.