Start with the COs you've already written off.

1. 01

   Log every change order

   Amount, project, GC contact, date submitted. Two minutes each.

2. 02

   Watch the clock run

   Aging buckets update on their own. You see what's gone past 90 before the GC does.

3. 03

   Escalate with the paper trail

   Every email, note, and attachment stays attached to the CO. Nothing to reconstruct later.