IMPRECISE COMPUTATIONS

The imprecise computation technique has been proposed as a way to hand le transient overload and to enhance fault tolerance of real-time syst ems. In a system based on this technique, each time-critical task is d esigned in such a way that it can produce a usable, approximate result in time whenever a failure or overload prevents it from producing the desired, precise result. This paper describes ways to implement impre cise computations, models to characterize them and algorithms for sche duling them. An imprecise mechanism for the generation and use of appr oximate results can be integrated in a natural way with a traditional fault-tolerance mechanism. An architectural framework for this integra tion is described.