I am using Gantter and/or ProjectLibre (which are both almost identical to Microsoft Project in functionality). I think that if there is a solution to this in Microsoft Project, then it will work in either of these too.
Here is the scenario:
Task 1: Work 5d (40h): Resource A
Task 2: Work 2d (16h): Resource B
Task 3: Work 20d (160h): Predecessor Task 2: Resources A and B
I would like Resource B to start Task 3 at the end of 2 days and Resource A to start Task 3 at the end of 5 days.
Note that "Work" above is the effort estimated by us for the task.
Ideally, Task 3 should start on day 3 with Resource B who should spend 11.5 days on it and Resource A should spend 8.5 days once Task 1 is done.
However, when I allocate 2 resources to the task with 100% units, it gets divided equally into 10 days each. The Task 3 starts on day 3 and I get over-allocated resources message because Resource A spends 3 days on both Task 1 and Task 3.
I know I can do this allocation manually by detailing the resource assignment. The question is can this be automated in some way? It's bizarre that this has to be done manually. I assume that it must be a pretty common requirement? Or am I mistaken?