Reference Model for Open System Interconnection

In 1980, General Motors (GM) experienced difficulties in getting the vendors to agree on specific standards. Also the standards are so broad that they have become very complex and hard to develop hardware and software for, thus driving up the costs. In the GM plants, there are thousands of computer controlled equipment which has become a nightmare to integrate. The fact is that no single vendor could meet all the needs, and multiple vendors caused communication incompatibilities.

Realising the problems, GM decided to begin the development of a networking protocol for the high data rates expected, while improving noise immunity for such computer controlled manufacturing environment. This scheme was expected to provide a common standard for all equipment to simplify integration. The aim of the task force is to develop an open heterogeneous factory communication network based on OSI model for all the processes involved in the manufacturing as detailed above.

The reference model for communication within open systems was established by International Standards Organisation (ISO) in 1983 in the form of Open System Interconnection (OSI) model as shown in Table 1. This is the basis for the architecture of many proprietary communication networks.

Table 1 : Reference Model for Open System Interconnection (OSI) Model ISO DIS 7498-1983