This example describes an on-line medical management system which handles patient appointments within a health care institution, either with general practitioners, or specialist doctors.

The Client can first log on to a server by sending his/her user name and password (login!). Then, he/she asks for an appointment with a general practitioner (reqDoc!) and receives an appointment identifier.

Service MedServer first receives the patient name and password (login?). Next, this service can receive and reply a request for an appointment with either a general practitioner (reqDoc?) a specialist doctor (reqSpec?).

The Compatibility Matrix:

Analysis:

The Client and MedServer protocols are compatible with respect to the unspecified-receptions compatibility notion. The Boolean compatibility can be detected from the matrix since the initial states c1 and s1 are compatible (compatibility degree is equal to 1). Therefore, the global compatibilty degree of these protocols is equal to 1.

The unmatched message reqSpec?, going out from s2, does not cause an incompatibility issue since it is considered an additional reception, and the state s2 remains compatible with c2.