Resources that do not drive the dates of the activity to which they are assigned are considered to be nondriving. You can define resources as driving or nondriving by default in the Projects Window, Project Details, Resources tab. When scheduling nondriving resources, P6 Professional applies the following rules:
- When scheduling on the forward pass, if the activity has any driving resource assignments, P6 Professional calculates the early start date of the activity as the earliest Early Start date of all driving resource assignments. Once the Early Start of the activity is calculated from the driving assignments and relationships, all nondriving resources are scheduled on or after this date using its assignment duration. The Early Finish dates of the nondriving assignments can fall earlier or later than the Early Finish of the activity.
- When scheduling on the backward pass, the Late Start date of the activity and all nondriving resources are calculated as the earliest Late Start date of all driving resource assignments. Once the Late Start date of the activity is calculated from the driving assignments and relationships, all nondriving resources are scheduled on or after this date using its assignment duration. This means the Late Finish date of the nondriving assignments can fall later than the Late Finish date of the activity to which they are assigned.
- The finish dates of the nondriving resource assignments can fall later than the latest calculated Early Finish date of the project, which is driven by the activity dates.
- If no driving resources exist on the activity, the activity dates are used as the calculated dates for the nondriving resources.