Open systems evolution

A brief overview is provided of open systems from the first proprietary systems to the current client/server systems. Future directions are also considered. Evolution of information systems is motivated by two factors; technology and business needs. Business needs always inspire technology development and set the main directions. On the other hand technology also impacts business needs by distinguishing what would be nice to have and what is affordable. The evolution began with isolated systems. Typical users were large enterprises with hierarchical organization. Typical applications were developed to support this hierarchical organization and to manage operational processes like order fulfilment, stock management, etc. Several vendors had different solutions and many customers developed their own applications. As these systems were isolated from each other there was no need for interoperability. As computers started to become widely used new requirements arose. The authors consider the UNIX, OSF and POSIX operating systems.