Perturbation analysis is a software analysis technique used to study the tail function of a program by inserting an error into an executing program using data state mutation. The impact of this induced error on the output is then measured. This methodology can be used to evaluate the effectiveness of a given test set and in fact can be used as a means to derive a test set which provides coverage for a given program. Previous research has shown that there is a "coupling effect" such that test sets that identify simple errors will also identify more complex errors. Thus the research would indicate that this methodology would facilitate the generation of test sets that would detect a wide range of possible faults. This research applies a perturbation analysis technique to the Cell Pre-selection algorithm as used in the Tomahawk Weapons Control System.