The dynamic reduction of fault simulation

Efficient strategies to perform selectively fault-free simulation, critical path tracing in fanout-free regions, and fault simulation of stem faults in a parallel pattern evaluation environment are presented and analyzed in an implementation-independent manner. The dynamic changes in the complexity of the fault simulation components as the fault simulation progresses and faults are detected are shown to be extremely significant. In particular, fault-free simulation tends quickly to become more expensive than both the critical path tracing within fanout-free regions and the explicit simulation of stem faults. In addition, the presence of redundant faults is shown to have an inhibiting effect on the reduction of the fault simulation complexity