PO Close Automation

Hello,

We are in the process of putting together criteria to evaluate creating a job to (1) mass close all POs that are at least 18 months old with no recent invoice activity  and (2) create a job that runs once a month to continue to close POs that are have been open for longer that 18 months (with no recent invoice activity).  Interested in knowing how other companies have accomplished this.  What evaluation criteria/ testing plan did you use?  Were the POs put in a Close or Final Close status?  What was the timeframe for 'recent invoice activity'?

Thank you in advance!

Melissa