Hi Christophe, thx for the fast response. I will check evaluate your suggestion as fast as possible. I have another issue with MSM: Is there a possibility to model a "do:)"-activity within a state (some UML modelling tools like enterprise architect support this kind of activity)? This means an action which is executed between the entry-Action ( void on_exit (...)) and the exit-action (void on_exit (...))? Maybe this can be solved by using an internal transition within a state which defines among the entry- and exit function additionally the functor "operator ()(...){// Do something state-specific}" ?! It would be great IFA you could provide me within something information if MSM supports such "Do"-activities in a state. Thanks in advanced, RaRi -- View this message in context: http://boost.2283326.n4.nabble.com/Boost-MSM-Ignore-events-that-were-not-exp... Sent from the Boost - Users mailing list archive at Nabble.com.