Task A schedule 6/1-6/10
Task B will start from A finished, its schedule is 6/11-6/20
Task C will start from B finished, its schedule is 6/21-6/30
If Task A postponed 6/1-6/15
Task B could auto changed 6/15-6/25
Task C could auto change 6/26-7/5
How to make the "auto change" happen?