Impact of Microsoft Project Rules on Fields

Microsoft Project maintains internal rules that determine the way field values are calculated in planning and actuals fields. These rules affect the synchronization processes between Microsoft Project and Project Management because calculations that work in one application do not necessarily carry over to the other application.

For example, Project Management allows you to retain actuals information that is completely separate from your schedule information. In Microsoft Project, this is not allowed, and making updates to one actuals field may trigger automatic revisions to other planning and actuals fields.

The most common Microsoft Project rules for planning and actuals fields are listed below.

Planning Fields

  • Start + Duration = Finish

  • Effort = Duration * (sum of resources * units)

Actuals Fields

  • Start = Actual Start (if known)

  • Finish = Actual Finish (if known)

  • Duration = Actual Duration + Remaining Duration

  • % Complete = Actual Duration / Duration

  • Remaining Duration is zero when task is 100% Complete

  • Effort = Actual Effort + Remaining Effort

  • % Work Complete = Actual Effort / Effort

When Project Management information is passed to Microsoft Project, Microsoft Project will always apply its standard rules. This will lead to situations where the data in each application does not match exactly.