Thank you for the response. I have moved generation of the event "last_state" to main function instead of the payment_done struct (I have attached the code too. As I mentioned the code and some logic is not sophisticated.) and the code seems to be working. However if I want to make an auto-transition from the Payment sub-machine (once it reaches the final "payment_done" state) to the next state in the vending machine how do I do that? I tried to declare en exit_pseudo_state without an event (struct payment_done: public exit_pseudo_state<last_state>) and then declare an auto-transition from "Payment" submachine to "waiting" state in the vending machine (Row < Payment::exit_pt<payment_done>, none, waiting, dispense_item, none>) but I am receiving compilation errors. I have another question to ask. If one wants to access info stored in one state from another state, what will be an elegant way to do that? For eg. In case of the vending machine example, lets assume the selection state stores the product selected by the customer. This info then needs to be accessed while dispensing the product at later stages. One way could be storing pointers to all the instances of structs that represent state in the state machine. However in this case submachines may not be able to access the info stored in the parent machine. Thanks! http://boost.2283326.n4.nabble.com/file/n3572332/vending_machine.cpp vending_machine.cpp -- View this message in context: http://boost.2283326.n4.nabble.com/Boost-MSM-Can-not-get-out-of-the-submachi... Sent from the Boost - Users mailing list archive at Nabble.com.