Begin date calculation based on (multiple) end date dependency

[Jacobs87]

Hi all,

I have an Excel challenge which I cannot get my head around. I have a planning sheet with multiple tasks and duration, which all have a start and end date. However. Some of the tasks are dependent on others. In other words: the start date of a task X could be dependent of task Y.

[TABLE="width: 500"]
<tbody>[TR]
[TD]ID[/TD]
[TD]Task[/TD]
[TD]Duration[/TD]
[TD]Start[/TD]
[TD]End[/TD]
[TD]Dependency task[/TD]
[/TR]
[TR]
[TD]1[/TD]
[TD]A[/TD]
[TD]2 weeks[/TD]
[TD]1-1-2018[/TD]
[TD]14-2-2018[/TD]
[TD][/TD]
[/TR]
[TR]
[TD]2[/TD]
[TD]B[/TD]
[TD]1 week[/TD]
[TD]14-2-2018[/TD]
[TD]21-2-2018[/TD]
[TD]2[/TD]
[/TR]
[TR]
[TD]3[/TD]
[TD]C[/TD]
[TD]2 weeks[/TD]
[TD][/TD]
[TD][/TD]
[TD]2[/TD]
[/TR]
[TR]
[TD]4[/TD]
[TD]D[/TD]
[TD]3 weeks[/TD]
[TD][/TD]
[TD][/TD]
[TD]2,3[/TD]
[/TR]
[TR]
[TD]5[/TD]
[TD]E[/TD]
[TD]1 week[/TD]
[TD][/TD]
[TD][/TD]
[TD]3[/TD]
[/TR]
</tbody>[/TABLE]

Anyone with an idea?