Time management PCR Operation

Hello SAP Experts,

I need to know the following:

01. The basic functionality of the time evaluation program in terms what is the input used, processing and the output produced.

02. The most common operation used in PCRs for time management and the functionality of each.

Note: that we're using positive time management that is integrated with time recording machine.

Please consider it a matter of high importance.

Your help would be highly appreciated.

Thanks and regards,

Sally