Low and high duration for summary tasks

[Ken]

When I use the add in with MS project 2010 why does the program calculate low and high durations for subordinate tasks but does not for the summary task. I would be pleased if you could advise me where i am going wrong.

[Intaver Support]

In Microsoft Project, summary tasks are inert and all they do is provide a rollup of the underlying subordinate tasks. The same is true for our simulations; we can only use the subordinate values as inputs.

If we edited the low and high summary estimates, it would give the appearance that we are using the summary values for the simulation, which would be incorrect and could possibly create discrepancies between probabilistic results for the summary and subordinate tasks.
Therefore to ensure there is no misunderstanding, we do not modify the values for the summary activities for the Low and High Duration columns.