AN ANALYSIS OF TEST DATA SELECTION CRITERIA USING THE RELAY MODEL OF FAULT-DETECTION

RELAY is a model of faults and failures that defines failure condition s, which describe test data for which execution will guarantee that a fault originates erroneous behavior that also transfers through comput ations and information flow until a failure is revealed. This model of fault detection provides a framework within which other testing crite ria's capabilities can be evaluated. In this paper, we analyze three t est data selection criteria that attempt to detect faults in six fault classes. This analysis shows that none of these criteria is capable o f guaranteeing detection for these fault classes and points out two ma jor weaknesses of these criteria. The first weakness is that the crite ria do not consider the potential unsatisfiability of their rules; eac h criterion includes rules that are sufficient to cause potential fail ures for some fault classes, yet when such rules are unsatisfiable, ma ny faults may remain undetected. Their second weakness is failure to i ntegrate their proposed rules; although a criterion may cause a subexp ression to take on an erroneous value, there is no effort made to guar antee that the intermediate values cause observable, erroneous behavio r. This paper shows how the RELAY model overcomes these weaknesses.