SAP worked great when PSA was a 700 pilot airline. If you put in a request at the opening minute, you'd get an approval within ten minutes or so.
Then PSA grew to around 1,100 pilots, and that same transaction started taking 4-5 hours. Then the SAP started crashing almost every month.
Finally we were able to get them to split the SAP between Captains and First Officers, and remove some of the company-placed restrictions, which cut in half the load on the system, and reduced delays significantly...though those "first minute" transactions still tended to take 1 1/2-2 hours.
Now we've added another 600 pilots. The results are predictable.
This month I placed my first transaction around 9 p.m., and got it approved at 2 a.m.