SLA compliance as a record, not an argument.

An SLA that nobody measures is a sentence in a contract. Measuring it by hand is worse, because the measuring stops the moment things get busy.

The record is the report

Every file exchange is logged with an audit timestamp. Reports go out daily, weekly or monthly, which means compliance is something you look up rather than something you reconstruct after someone complains.

Told at the time, not at month end

Email alerts fire when an SLA rule is breached. The value is in the timing: a late file you hear about at nine is a phone call, and the same late file heard about at month end is an incident report.