Let us say I have 3 tasks (A, B, C), all of them occupy 100% of the resource "CAESAR". Task A must be completed before any of task B or C can even start. Task B or C can be completed any time before the project ends, but can start much later (but not before as said) the time when task A ends.

I can of course link those tasks via Finish-to-start (FS) (EA in German) - that enforces the task B to start immediately after completion though. I could add lag time, but to my knowledge that is an exact lag, and not a minimum (such a "dynamic" lag would be 0 days in my case, since both tasks B and C could but not have to start immediately after A finishes). The bigger problem, however, is this: When I link both B and C to the finish time of A via FS, I always get resource conflicts since B and C are then set to BOTH start at the end of A, which is not possible as the resource (here "CAESAR") is required 100% by both tasks. I can resolve them manually of course, but I would have expected C to start after B then by default (as it is in the row below B, see red box in attached screenshot). Is there a way to achieve this?

Attached Images

link_tasks_with_dynamic_lag.JPG (23.4 KB, 12 views)

Microsoft Project does not work the way you expect it to do. If you do not know when tasks B and C will start, how would the software know? I would recommend you schedule these two tasks with a Finish-to-Start dependency between them, which would remove the resource overallocation. On the FS dependency between tasks A and B, you might want to enter a Lag time value of 10d or something like that to show that task B does not start immediately when task A is completed. Hope this helps.

Hi Dale, first of all thanks a lot for your quick reply! I might have oversimplified my example, my bad: Why I was not happy with FS in the first place might become more clear when I adapt the example as such: task C now requires not only 100% CAESAR but also 20% BRUTUS (task A and B remain 100% CAESAR only). BRUTUS happens to have 2 days availability only after task A ends (ergo Wednesday and Thursday are free, but not Friday when you compare it to the above screenshot).
My hope now was that task C would be shifted to the available resource "gap" Wednesday+Thursday before task B as both are free to be shifted around (as long as it's not earlier than the finishing of task A). Task B would then start on Friday. This was not possible if I had connected them via A -> (FS) -> B -> (FS) -> C. Any idea how to adress this? Thanks, Chris

There is no way to model the behavior you are seeking in Microsoft Project. Sorry.