Hard to find a short but explicit title for this topic.
I am rendering horizontal bar chart showing tasks schedule.
for each task I have a
- customer available time
- scheduled time
- actual completion time
- due date
Depending on the tasks, showing those four data can lead to almost empty graph, here are examples :
Good looking :

Bad, because there is a wide area with no data :

Bad because there is a wide area with only the same data (green):

What I would like to have is to adapt scale locally so that data are more visible, like this (paint edited) :

As you can see, there are gaps in the range axis (PlotOrientation.HORIZONTAL).
So I would like to have hints / suggestions about the way I could to this. I was thinking about putting several graphs together but I I am not sure it is the easiest/best way to handle it.
Thanks for any input.