Constraints in predecessors in SmartSheet ?

edited 12/09/19 in Smartsheet Basics


I want to create the gantt with schedue as below:

Task A

   Subtask A1    Oct 15 to Oct 19

   Subtask A2    Oct 15 to Oct 19

   Subtask A3    Oct 22 to Oct 26

   Subtask A4    Oct 29 to Nov 2


Predecessors of A3 = Subtask A1 and Subtask A2

Predecessors of A4 = Subtask A1 and Subtask A2

Subtask A3 and Subtask A4 are assigned to the same resource and the resource is expected to start with A3 first and A4 later.

However, SmartSheet does not support this input and result an error when I amend the start date of Subtask A4 to Oct 29.

Is this is the "constraint" of Smartsheet on this? And why?

Thanks and regards