On human reliability trends in digital communication systems

Abstract Communication system structure is undergoing a significant change: yesterday's massive collection of discrete devices hardwired into fairly simple architectures is in the process of replacement by tomorrow's highly versatile control system driven by a stored program and the whole scheme implemented with very reliable digital LSI devices. Past experience indicates that the integrity of such systems is likely to be greatly influenced by the mode of interface between these complex, intelligent yet abstract machines and the ordinary human user. This paper first discusses very briefly the future trends in the digital communication systems and then presents a system analysis model in the form of a state diagram which may be used hopefully to study the overall availability behaviour of next generation digital communication systems. The emphasis in this paper is mainly on the human reliability aspects. Man-machine reliability which is fast becoming a practical engineering parameter for reliable system designs is briefly discussed emphasizing a life-cycle oriented system development approach.