Unexpected behavior of rubber link and start-finish type


(Johannes Mulder) #1

Hi,
for me the behavior of rubber link combined with start-finish type seems strange

I expect a start-finish link should require to have the depending task finished before the start of the ‘master’ task. This seems to be working.
When I change the link from Strong to Rubber, I can move the depending task to after the ‘master’ task, and not earlier. In this way the requirement seems to be violated.
I would expect to be able to move the depending task earlier, so the requirement is still fulfilled.

Or did I not grab the proper function of the this type?

Johannes


(Dmitry Barashev) #2

I can agree that it works not as one may expect. However, it works “as designed”, in the sense that it follows the definition of “rubber” dependency implemented in code.
We have plans of replacing rubber dependencies with equality/inequality conditions on predecessor and successor dates, which will allow for stretching the dependencies in both directions.

As a current workaround, will it help if you just reverse the dependency and make it Finish-Start?


(Johannes Mulder) #3

Seems that the plan to change this allows for more flexibility, which is never bad.
You might be right with reversing the dependency. I used the Start-finish because it matched my way of thinking for this case.
Still, with a start-finish dependency having the finish later than the start sounds not logical to me.
Would be helpful to have some examples how one could use these features.
I think many users are not experts in Gantt charts. At least, I am not :slight_smile: