Data provided in subject Area Procurement - Purchasing Real time

Summary

Data from Purchase Order Pre-processing Days inconsistent

Content

I am having difficulty obtaining metric information.

I am working with OTBI and trying to get the cycle time between requisition last approval date/time and the  date/time the PO is created.  I am using the Procurement – Purchasing Real Time subject area.  Under Purchase Order Header there are two options that I am using:  Purchase Order Pre-processing Days and Purchase Order Approval Processing Days (to track how long PO approvals were taking). 

I was hoping to obtain date on the number of days from the last requisition approval date to PO creation date in the Purchase Order Pre-processing Days (optimally with data display 3 places to the right of the decimal to account for partial days.