Component based message alerting is the way forward and recommended approach.But you also have choice to switch to the classical approach of Alert framework with tcode ALRTCATDEF for creating alert category and setting rules in RWB. For details please check http://help.sap.com/saphelp_nw73ehp1/helpdata/en/b2/58b14b70744d0db55599230d2c5bce/frameset.htm
Regards,
Sunil Chandra