throw an error after a BPM step with understandable answer

Hi

I am using a BPM and I would to throw an error after a step with understandable answer so as to be seen from SXMB_MONI or from the content of the message. I use an alert to throw the exception but it is not so oprical good. Do you have any idea , Do you think that i could use a trick transfrmation step for exception using a fault structure ?

Antonis