prim32871:What is the difference between Early Start, Remaining Early Start and Start?

The Early Start date is calculated during the forward pass of scheduling and takes into account relationships, logic, constraints, scheduling rules applied, resources, etc. The Early Start date is the earliest possible time the Remaining duration of the activity can start. 

The Remaining Early Start date is calculated during the forward pass of scheduling in the same way that the Early Start date is calculated. The Remaining Early Start field can be manually updated, but unless constrained, will be recalculated to the Early Start date the next time the project is scheduled.

The Start date is the beginning date the activity. It is set to the Actual start if the activity has started and is set to the Remaining Early Start for unprogressed activities. 

Note: Unless the Remaining Early Start is date is manually updated, the only time the Remaining Early Start date and the Early Start date are not the same is when leveling resources and choosing to preserve Early Dates (Tools, Level Resources, then mark the option to ‘Preserve scheduled early and late dates’). In this case the Early start date represents the scheduled start date and the Remaining Early Start date represent the leveled start date.

ON: Preserve Scheduled Early and Late Dates

Forward levelling pass performed

Early Start and Early Finish – Scheduled Early dates

Remaining Early Start and Remaining Early Finish – Levelled Early dates

Remaining Late Start and Late Finish – Scheduled Late dates

Remaining Float – Levelled Float

OFF: Preserve Scheduled Early and Late Dates

Forward and Backwards levelling pass performed

Early Start and Early Finish – Levelled Early dates

Remaining Early Start and Remaining Early Finish – Levelled Early dates

Remaining Late Start and Late Finish – Levelled Late dates

Remaining Float – Levelled Float