IDOC Monitoring end to end

Dear Experts,

Need you help to work on IDoc monitoring.

1. How to check whether the IDOC reached to PI from Source or Not ?

2. How to check whether the IDOC is posted at target end or not ?

3. How to check the IDOC if they any where stucked ?

4. What are the activities we have to do if the IDOC is not reached to PI and If the IDOC is not Posted at target end

5. How to get the Payload using only IDOC Number ?

6. What are the monitoring activities we have to do even the status code it is showing 03 in PI but IDOC not reached to PI

7, What are the other things we have to monitor for end to end for IDOC monitoring and fixing the bugs

Thanks in Advance

Regards,

T.