Aggregate line graph using three fields

Hi,

I am trying to create a line that follows progress on 43 purchase orders (POs) in a project. Each purchase order has a date for baseline, a date for forecast, and a date for actual achieved. I want to create a graph illustrating the trend in each of these. The plan will be updated continually until all POs are placed. I want a graph that looks more or less like this.

Instead og managing to get the graph I want, I used a work-around where I actually created three separate graphs that I placed above eachother, where all Axes are completely fixed. This is, of course, only a temporary remedy.

How can I create this graph without having to create three separate graphs? I currently have the three fields, where I am getting aggregates by creating a Quick Measure for running totals of each field. When I try to add a second field to the Values of any of the graphs, it stops show aggregate info, and instead looks like this:

Any tips would be great!