Hi Christophe I'm running the attached test program it generates the following output : entering: Idle MS1_ leaving: Idle Action: MS1::onEvent1 entering: RunningStateMachine MS1_ entering: RunningStateMachine::PseudoEntry1 leaving: RunningStateMachine::PseudoEntry1 entering: Inner1 RunningStateMachine_ entering: InnerState11 FwdGuard: returns:0, event: event5 FwdGuard: returns:0, event: event1 FwdGuard: returns:0, event: event1 FwdGuard: returns:0, event: event5 FwdGuard: returns:0, event: event1 FwdGuard: returns:0, event: event1 FwdGuard: returns:0, event: event5 FwdGuard: returns:0, event: event1 FwdGuard: returns:0, event: event1 FwdGuard: returns:0, event: event5 I believe it is incorrect after state machine entered state InnerState11 . FwdGuard should have been called ones with event5 and than 3 times with event1 and event1 shall have triggered after the first dispatching a no transaction. But this case no trans was triggers on even1 and and the deferred event5 got dispatched even there was no state change for every event1 dispatching. this breaks our code execution completely :(. Br. Richard