Jean-Marc Andreoli, Stephen Freeman, Remo Pareschi
Journal of Theory and Practice of Object Systems (TAPOS), 2(2), pp 77-94, 1996
The development of communication infrastructures and the rapid growth of networking facilities in information
technologies increase information mobility and the decentralisation of work processes in industry and services.
This evolution leads to increasing demands on the coordination of information systems. However, information
technologies available today are capable of supporting only interoperability of information systems from the
point of view of communication infrastructures. This makes possible an easy exchange of information but
provides no support for coordination. To fill this gap, we propose the Coordination Language Facility (CLF) as a
coordination layer on top of distributed systems infrastructures such as CORBA-compliant Object Request
Brokers. The CLF provides support for the coordination of heterogeneous, possibly distributed, active objects
within larger units implementing (work) processes. On one hand, coordinator objects are declaratively
implemented as rules. On the other hand, the objects participating in a coordination (participants) must
instantiate a minimal interface which specifies the negotiation dialogue invoked, at run-time, by coordinators.
The coordination activity is split between the implementation of the interface on the participantsside and the
execution of the rules on the coordinators side, thus offering a clear separation of concerns between local and
global activities. The interface is specified using the CORBA standard for distributed objects, removing issues
of heterogeneity and allowing each component to be implemented in the most appropriate language and
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