mclaubee -
I think we need more info. Are you trying to control chart multiple characteristics of a single part? e.g. lenght and weight of a part.If so, start off with "Advanced Topics in SPC", Wheeler, Chapter 15.
The internet search most likelky to be fruitfull for this is "Hotelling's t squared."
I found this link which might help.
http://www.itl.nist.gov/div898/handb...on5/pmc543.htm
Darius is interpreting your need as being to do short run SPC e.g. lenght of part number 123, equivalent lenght of part 456. The references he cites are excellant for that situation if that is your case.
Juran's (as usual) treats both these in the control chart section ( chapter 45 of the 5th ed) , but is pretty skimpy.
PS I won't be able to give practical advice on either as all my experience has been more prosaic. You must have some "kewl" applications as my kids say, if you are considering these exotic types.
Wonder if common Shewhart techniques might do you just as well.
Only one old dog's opinion.