Sum of sub task logged hours shall be rolled up and shown against parent task

Effort spent on a sub task should be rolled up as sum and displayed with same field(or custom) against parent task.
By this, we can plan for a entire task and allow multiple resources work on the sub tasks. As a control mechanism manager can used the total efforts spent (summed up hours) in parent task.
One can just track parent tasks for efforts spent against planned.

Under consideration for V2 of SmartTask