How to create chart with x and y axis

[#1]

Hi,

I am trying to create a chart that shows the Name on the Y-Axis, with the Activity Date on the X-axis, with System as another dimension(3-each a different colour)

Everytime a student has a date(ActivityDate), I want to show a dot(bar) on the chart- Similar to the one in my example.

I think I may need to play around with the Bar offset expression, but I am not sure how to get this to work?

I've attached my .qvw, along with the image of what I want the chart to look like.

Any ideas?

Thanks!

[#2]

I've managed to kind of create the chart I'm looking for, but not sure how to get only 3 colours showing in the blocks(bars).

I only want 3, for each System, as I've created on the attached model.

Any ideas?

Thanks..