I have a problem to create a chart. I have this data:

Machine part minute start minute stop
G A 0 282
G B 282 359
Ma C 0 298
Mb D 0 183
Mb E 183 497
Pa F 110 278
Pb G 0 172

I want a chart with bars which draws the time that each part is in each
machine like this for machine G:

----------A----------
------B-----

But I don't know how to do this, could you help me??
If you don't understand anything of the question please ask me, I know my
english is terrible!

Thanks!
--
atrep