UN/CEFACT’s modeling methodology (UMM) is a UML profile for modeling global B2B choreographies. The current UMM version comprises three main views for describing a computation independent model from a neutral perspective. Currently, the UMM version is missing a platform independent model showing how each partner has to realize the message exchanges to support the agreed choreography. In this paper we derive such a platform independent model from a UMM business transaction - a key artifact of the computation independent model. The resulting model is based on a state machine describing the local view of a participating business partner. This state machine unambiguously defines how a business partner has to react on incoming messages and on message expected but not received.