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Messaging in the Process Specification Language



Conrad Bock, Michael Gruninger


This paper characterizes messages by the constraints they place on participation of entities in processes. Constraints are expressed in two ways: informally as usage patterns of the Process Specification Language, and formally as extensions to it. The extensions reduce ambiguity and increases expressiveness compared to conventional process modeling languages, by defining the relation of the extensions to existing PSL execution concepts. Examples drawn from a spectrum of message types illustrate the range of variability in the reaction of the message receiver. The extensions are used to formalize message forwarding, a useful technique in specifying composable processes. These suggest simpler alternatives to formalize inputs and outputs.
NIST Interagency/Internal Report (NISTIR) - 7258
Report Number


messages, process model, PSL


Bock, C. and Gruninger, M. (2005), Messaging in the Process Specification Language, NIST Interagency/Internal Report (NISTIR), National Institute of Standards and Technology, Gaithersburg, MD, [online],, (Accessed May 24, 2024)


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Created August 31, 2005, Updated October 12, 2021