It is important to understand that OSI is concerned with the exchange of information among open systems, not with the internal functioning of each individual "real" open system. A "real system" in this context is one that complies with the requirements of the OSI Model in its communications with other "real systems." A real system is, therefore, a set of "one or more computers, associated software, peripherals, terminals, human operators, physical processes, information transfer means, etc., that forms an autonomous whole capable of performing information processing and/or information transfer. Within an open system, an application-process performs the information processing for a particular application.
Aspects of systems not related to interconnection are outside the scope of OSI. This still leaves broad scope for OSI, for it is concerned not only with the transfer of information among systems, but also with their ability to interwork to achieve a common or distributed task. This is implied by the expression "systems interconnection." The fundamental objective of OSI is to define a set of Recommendations to enable open systems to cooperate. Cooperation involves a broad range of activities:
1. Interprocess communication: the exchange of information and the synchronization of activity among OSI application-processes.
2. Concern with all aspects of the creation and maintenance of data descriptions and data transformations for reformatting data exchanged among open systems.
3. Concern with storage media and file and database systems for managing and providing access to data stored on the media.
4. Process and resource management by which OSI application-processes are declared, initiated, and controlled, and the means by which they acquire OSI resources.
5. Integrity and security of data during the operation of open systems.
6. Program support for comprehensive access to the programs executed by OSI application-processes.
Since some of these activities may imply an exchange of information among the interconnected open systems, they may be of concern to OSI. I am sure that my buddy Don will throw in some comments below if I get any of this wrong since he worked on building these standards!