Thank you for your email. Aside from fire drill finding, your factory has to conduct external inspection for fire hydrant system at least once a year.
Please do not just rely on the previous audit findings, because there could be another finding will be captured by the next auditor.
Your best reference for the audit is WM Suppliers Manual and Fire Safety Training Module documents.
Please reach out to the supplier (copied on this email) for the references needed if you still don’t have it. Thanks.