Creation of Preventative Maintenance work order based on meter readings.

One of our client requires to use Meter Readings to suggest/generate Preventative Maintenance Work orders. Oracle white paper issued in May 2015 suggested to define meters as follows "Rate per day" = 1 and "No of Past Readings" = 999999. This will result usage rate to stay same as 1 and the PM scheduler would not re-calculate the usage rate.

Set ups are performed, however we have faced two situations:

1: At PM Schedule definition form, we used Actual start date as Scheduling option

2-At PM Schedule definition form, we used Base Meter as Scheduling option.

The set ups per the white paper results in work orders being suggested either 10-15 years in future or past. Please guide what are we missing to gain the intended functionality of the said meter setups.