Gantt Suite supports dependencies with lead and lag.
Lag refers to the amount of time that is added between a predecessor task and its successor. Lag is a delay.
Lead is the amount of time by which a successor task can be advanced with regard to its predecessor. So lead is a kind of negative lag.
It is possible to set a delay (gap) between tasks by moving successor task after the predecessor via drag & drop, or by editing task start date. But autoscheduling might eventually move successor right after the end of predecessor. Additionally, critical path visualization isn’t working correctly if there is a gap between tasks that is not set up as a lag of the dependency.
There are few ways to set lead or lag for a dependency, once you hover over it:
This will open the dependency edit dialog.
Set the desired lead or lag and click Save.