Effect of fault distribution and execution patterns on fault exposure in software: a simulation study

Execution patterns and fault distribution characteristics of a program will affect the failure process and thus reliability estimates, The failure pro cess of a software system is influenced by many factors, and traditional so ftware reliability engineering has found it difficult to isolate the effect of each individual factor, A simulation approach is used to investigate th e effects of fault distribution, execution pattern and program structure on software reliability estimates. A reliability simulation environment (RSIM ) Is extended by introducing variable fault distribution patterns in its co de generation phase. Flow control points allow varying the execution freque ncy of different parts of a program, The simulation results show that fault distribution patterns and execution patterns have dramatic effects on faul t exposure rate, If the fault distribution is non-uniform, a non-uniform co de execution exposes faults more efficiently and effectively than uniform e xecution. Results also show that the structure of a program affects fault e xposure rate and testing time required. Copyright (C) 2000 John Wiley & Son s, Ltd.