1. A system comprising: one or more computers; and a computer-readable medium coupled to the one or more computers having instructions stored thereon which, when executed by the one or more computers, cause the one or more computers to perform operations comprising: displaying a first process model that is executed by a first entity in a first computing environment and a second process model that is executed by a second entity in a second, differing computing environment, each process model being pre-defined and including a progression of task nodes, and coordinator nodes that coordinate the progression of the task nodes; inserting a sender task into the first process model to provide a modified first process model, the sender task including an event identifier, a first entity identifier and a second entity identifier; inserting a receiver task into the second process model to provide a modified second process model, the receiver task corresponding to the sender task of the first process model, and including the event identifier, the first entity identifier and the second entity identifier, the sender and receiver tasks transferring control between the first entity and the second entity; generating an intermediate process model based on the modified first process model and the modified second process model; inserting control flow coordinators within the intermediate process model based on locations of the sender and receiver tasks to provide a merged process model; identifying a transition that connects two or more particular control flow coordinators; identifying a closed sub-graph including the two or more particular control flow coordinators; and based on identifying the closed sub-graph, removing the transition and the two or more particular control flow coordinators to provide a sequential process model.