ABSTRACT
This chapter proposes a distributed online safety monitor based on a multi-agent system and knowledge derived from design models and a safety assessment model of the monitored system. It examines a distributed safety monitor by synthesising the benefits of two strands. The first is the exploitation of knowledge obtained from the application of a model-based safety assessment technique architecture analysis and design language. The second is the distributed reasoning of multi-agent systems. The chapter describes the nature of the monitored system, that is, modern critical systems. It presents the position, role and constituents of the monitor and analyses the monitor through the application to an aircraft brake system (ABS). The main function of ABS is to slow down the aircraft during the taxiing and landing phases and achieve safe retardation in the case of a rejected take-off. The basic components of ABS include valves, sensors and three redundant pressure lines: normal, alternative and accumulative lines.
