See exactly what changed between two schedule updates.
What it does
Compares two Primavera P6 (.xer) schedule updates activity by activity and reports everything that moved: added, deleted and renamed activities, changed durations and logic, shifted dates and float, constraint and calendar changes, cost and resource changes, plus data-quality and update-integrity flags. Activities are matched by their Activity ID, so a re-numbered export doesn't produce false differences.
Two updates side by side: what was added, removed and moved is called out.
What it helps you achieve
Find out what a contractor's update actually changed, instead of trusting the narrative that came with it.
Spot logic, duration or constraint edits that quietly moved the finish date.
Catch update-quality problems (percent complete that didn't move, actual dates that reverted) before they reach a claim.
How to run it
Where to find it: Project page → Compare
Upload at least two .xer files to a project (Upload a schedule).
Open the project and choose Compare, then + New comparison.
Pick the Older schedule and the Newer schedule. You can pick them in either order: they are automatically placed by their data dates, and every finding reads older → newer.
Set the Near-critical threshold (working days; the default is 5) and choose Compare.
Read the Comparison dashboard: the summary counts first, then the sections (Schedule Changes, Calendars, Missed Dates, Data Quality, Absolute Float, and more).
Choose Download Excel to pick which sections go into the workbook.
What you get
A dashboard of every category of change, with counts and drill-down tables.
Near-critical float crossings: activities that became or stopped being near-critical between the two updates.
A saved result you can reopen from the history list at any time.
An audit-ready Excel workbook, one sheet per category.
Good to know
Results are cached: comparing the same two files with the same settings reuses the saved result instead of recomputing. Use Force re-run to recompute.
The same comparison can be overlaid on the Gantt so changed activities show a ghost bar of where they used to be.
Limits, stated plainly
It compares what P6 stored in each file. It does not recalculate the schedules (that is what Time Impact Analysis and Collapsed As-Built do).
Try Schedule comparison on your own schedules. Claims Digger is invite-only while we’re in early access.
No. The two files are placed on the correct side by their own data dates, so 'Added' and 'Deleted' always describe older → newer. A note appears if the files look like they were picked backwards.
What file format do I need?
A Primavera P6 .xer export. Each project can hold as many schedule files as you like.