Hi,
About your 1st Query,
Function P2011 is evaluating the data of IT2011 that is TEVEN table and as a output generate the TIP table.
This TIP table is further proceed through P2001 or P2002 if there have any entry's are there for IT2001 and IT2002 and final time pair is generated and shown under TIP table.
After evaluating entry of time data in the time schema then it's further evaluated through some of the standard PCR like TE20 , TE30 that time pair formation is correct or not as per the DWS the current day processing.
About your 2nd Query,
ERT table contains the message from the last evaluation run. If there have any error message is there from last evaluation run then system will go back and run from that point in the current time evaluation run.
Regards,
Sankarsan