Bar Charts that Don't Start at the Same Point?

[Stars]

Hi - 

Is there a way to specify where a bar chart starts that would be unique for each bar?  I'm trying to show service life for components on a chart.  Right now I've created a stacked bar graph with Year of Installation in white, then Service Life in gold.  The service life shows when the part will be operational and the year of installation part is virtually invisible.  Works fine.

However, I'd like to add other components to the same graph (right now I have just one component for multiple companies).  I can do paired bar charts, but the paired bars can't both be stacked, so I'm having a hard time figuring out how I would show other things on the same graph.  Sorry if I'm not explaining this well!