Hi Monika,
you are right... I missed the point...
and also as per sap note
- Web Service Message Monitor
The new Web Service Message Monitor (transaction SRT_MONI) has been optimized for Web Service Plain SOAP communication and the integration of related tools like the suite of supportability tools SRT_UTIL. If Web Services communication is used without PI, the Web Service Messaging Monitor can be used as the starting point for monitoring asynchronous calls. If the PI Web Service Adapter is used, the Web Service Message Monitor can be used as an adapter monitor in addition to the PI Message Monitor (transaction SRT_MONI).
So you can not monitor sync web service in SRT_MONI.