Compare Schedule Versions

Compare versions to see what changed between a schedule's versions.

Compare mode supports the standard features of the Schedule tool, such as searching, grouping, and filtering, for the latest version only.

To compare the schedule's versions:

Open Version history and click Compare.
Select the versions to compare. You can select up to 5 versions.

Version history showing schedule versions selected for comparison

Compare mode color-codes differences between schedule versions in List and Gantt views. Filtering, searching, and grouping, as well as configurable Gantt chart elements like dependencies, critical path, or resources, appear only for the selected version.

Compare mode adds two columns to the list:

Start variance
Finish variance

These columns show the differences in start and finish dates between the compared versions.

Note: Searching and filtering in Compare mode show only matching activities, not their parent tasks, so changes stand out. View mode shows matching activities with their parent tasks.

Compare mode with schedule changes shown in the List and Gantt views

Important: Compare mode compares each version to its predecessor. Other comparison modes aren't available yet.

Compare filters let you view only certain types of changes. All changes is the default. You can use Compare filters in different combinations.

Important: Compare mode compares all information in columns. To see the color-coded changes in the List view, turn on the columns where you expect changes.

Compare filters with the number of changes for each filter

Tip: Each filter shows how many changes it contains in parentheses.

Date-based filters support custom variance, which is the threshold at which a change appears in the filter. To set variance, select the number of days in the filter.

Variance setting for a date-based filter

Delayed start

The Delayed start filter shows activities whose start date moved later.

Delayed finish

The Delayed finish filter shows activities whose finish date moved later.

Advanced start

The Advanced start filter shows activities whose start date moved earlier.

Advanced finish

The Advanced finish filter shows activities whose finish date moved earlier.

In/out critical path

The In/out critical path filter shows activities that moved onto or off the critical path.

Important: To see these changes, add the Is critical column to the List view.

New

The New filter shows new activities that weren't present in previous versions.

Name change

The Name change filter shows activities whose name changed.

Removed

The Removed filter shows deleted activities that were present in previous versions.

Compare mode displays arrows that show the direction and impact of a change.

Arrows showing the direction and impact of changes

There are four types of arrows for current version changes:

Positive increment arrow for favorable increases in values like free or total slack
Negative increment arrow for unfavorable increases in values like start date or duration
Positive decrement arrow for favorable decreases in values like planned finish or remaining duration
Negative decrement arrow for unfavorable decreases in values like free or total slack

Note: Small color-coded arrows show differences between previous versions, so you can track changes when comparing more than 2 versions.

The Schedule tool matches activities between versions to:

Preserve references and comments
Track activity version history
Enable comparison of different versions

Users typically convert XER files to P6 before updating to a newer version. This conversion can create distinct IDs for the same activities across versions, which can complicate matching. The Schedule tool uses these matching methods to address this issue:

Unique ID (primary method): Matches each activity by its Unique ID. This method can fail when the same schedule is exported from multiple P6 projects.
Activity ID (alternative method): If matching by Unique ID isn't possible or doesn't succeed, the Schedule tool tries to match activities by user-defined Activity IDs or WBS codes. Changing the Activity ID or WBS code between versions can hinder this method.
WBS path (final method): If the previous methods don't succeed, the Schedule tool matches activities by their full path name, including all WBS parent elements. Changing the names of activities or WBS elements between versions can disrupt this method.

Important: Use unique activity names. Activities with the same names and WBS paths can cause mismatches.