Preserve both versions
Do not overwrite the old file. Label the two issues and retain their dates. A comparison needs an agreed baseline, not just the newest page.
Define what is being compared
A device quantity check, a specification review and a commercial contract review are different tasks. List the sheets and categories you expect in the deliverable.
Trace each difference
A useful change log identifies the old quantity, new quantity, difference and source location. Separate removed devices from existing devices that remain. Flag a relocated item so it is not mistaken for an additional device.
Reconcile the handoff
Check the change summary against the detailed register. Unclear symbols and conflicts should stay visible as questions instead of being silently resolved by assumption.
Published October 6, 2026 · Redline Estimating · Practical document guidance, not engineering or legal certification.