Open Systems

This chapter describes some problems and opportunities associated with conceptual modelling for the kind of “open systems” we foresee developing in the future. Computer applications will be based on communication between subsystems that will have been developed separately and independently. Some of the reasons for independent development are: competition, economics, geographical distribution, and diverse goals and responsibilities. We must deal with all the problems that arise, from conceptual disparities. Subsystems will be open-ended and incremental — undergoing continual evolution. There are no global objects. The only thing that all the various subsystems hold in common is the ability to communicate with each other. Message Passing Semantics is a methodology that we are developing to deal with highly parallel, distributed, open systems. Various aspects of this methodology deal with communication, description, transaction management, problem solving, change, completeness, and self-knowledge.