not so much dependency as you might think.

If you have a standard set of variables ( I tend to limit it to database connections for example)

having that drawn from parent...

As Lyn suggested you can do this by changing the value in a script.

Another way I have handled this (without using script) is to call a child package where it...

hmm maybe I should have done it that way.. all I did was write a little application that parsed the xml file, grabbed out all embedded sql statements and searched...