Information Systems: A Challenge for Computers and Communications Reliability

Modern information systems are the meeting point of the most advanced technologies both in the digital computers and in the telecommunications fields. Owing to their relevance on the everyday life, their availability became a major concern for system designers as well as for system managers. In this paper, we present an integration of the design and evaluation techniques as far as reliability and availability are concerned, in contrast with the duality existing between the computational functions and devices on one part and the telecommunications services and equipment on the other, which no longer snakes sense. To this scope, algorithmic components must be considered as part of the system, as well as the more traditional hardware and software components. A framework, including several research areas, is presented together with some results in the field of analytical models. The relations between the performance and the availability aspects in an Information System are also considered.