Dependable Computing and Assessment of Dependability

Inhalt:
This paper covers the main design and evaluation issues that are to be considered when developing dependable computer systems. In the first part it briefly addresses the fault tolerance techniques (encompassing error detection, error recovery and fault masking) that can be used to cope with accidental faults (physical disturbances, software bugs, etc.) and to some extent, malicious faults (e.g., attacks, intrusions). The second part covers the methods and technique - both analytical and experimental - that can be used to objectively assess the level of dependability achieved. The trend of controlled experiments, from simple fault injection-based tests meant for evaluating a specific faulttolerant computer architecture towards the development of benchmarks aimed at comparing the dependability features of several computer systems, are also briefly illustrated by means of selected examples.