If a task is estimated to take nine hours but can be done over three days, how should the Duration and Planned Hours be set up?

The correct approach is to set the Duration as 3 days and Planned Hours as 9.

This setup reflects that the task can be spread out over three days, allowing for flexibility in scheduling while still maintaining the total effort required for completion at nine hours. Duration indicates the total time frame in which the work occurs, not the cumulative effort, while Planned Hours captures the actual time estimation needed to complete the task regardless of the stretch of days. Therefore, by keeping the Planned Hours at 9, it accurately communicates the amount of work that needs to be dedicated to the task, even if it is performed intermittently over the three-day duration.

The other configurations would misrepresent the relationship between time and effort required for the task, leading to potential discrepancies in project planning and resource allocation.