Imprecise Computations

The imprecise computation technique has been proposed as a way to handle transient overload and to enhance fault tolerance of real time systems. In a system based on this technique. each time-critical task is designed 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 imprecise computations. models to characterize them and algorithms for scheduling them. An imprecise mechanism for the generation and use of approximate results can be integrated in a natural way with a traditional fault-tolerance mechanism. An architectural framework for this integration is described. © 1994 IEEE