Someone claims to have sent an IDoc from SAP ECC (or any other IDoc sender) to SAP PI, but it seems the message never arrived at the expected receiver. Or the other way around: an IDoc was expected in SAP ECC but never arrived. Below are the steps you can take to find out where the IDoc went missing. This will be your starting point for a more thorough investigation.
Note that I do not intend to describe all possible causes of IDocs going missing IDocs and their resolution.
For both directions (from and to SAP ECC) the basic steps are the same, but the implications are a bit different. I will therefore discuss these scenario’s separately.
IDocs SAP ECC to PI
IDocs SAP PI to ECC
If you cannot find the message in one of the steps above and you can find it in the next step, the cause of the problem must lie between those two steps, as described in my blog Interface Troubleshooting Basics. Focus your search in this area and, if needed, find possible solutions on SCN. Sometimes you may need to re-check previous steps after an insight you gained from later steps. For instance, the IDoc monitor may provide you with an IDoc number that you can use to re-check IDX5.