The sum of the elements at each level of the WBS considering "SS","FS"

[chamdan]

Enclosed is an example of what I am trying to achieve. The sum of the elements of each level of the WBS works fine but when the duration of a task is affected by the Task type such as: "SS" (Start to Start) or "FS" (Finish to Start) then the lower level does not reflect the real duration since the tasks may be working in parallel and therefore the sum accumulated of the sub-levels should take into consideration this task type.

I do not know whether this is clear but the example enclosed will provide you with clarification. In Cell D4, the array should consider the task type. In this example the duration should be 15 and not 21 since some of the sub-level tasks or activities work either in parallel or one after the previous would have finished.

Your help will be very appreciated.

Thanks in advance!