When I use to code in UNIX, I had an healthy appreciation on the program called MAKE. It would be something if SAS EG would run a program inside a process flow only if code inside a program had been modified since the last target was either created or modified or if the target had not been created yet.

I'm new to SAS EG, I do not know the ins-and-outs of conditional processing in EG yet.

For an example of SAS and MAKE see: http://support.sas.com/resources/papers/proceedings09/080-2009.pdf