Incomplete Tests for Undetectable Faults to Improve Test Set Quality

Abstract

The presence of undetectable faults in a set of target faults implies that tests, which may be important for detecting defects, are missing from the test set. This article suggests an approach for addressing missing tests that fits with the rationale for computing an n -detection test set. The artcile defines the concept of an incomplete test that is relevant when a target fault is undetectable. An incomplete test activates the fault but fails to detect it because of one or more assignments that are missing from the test. The procedure described in this article improves the quality of a test set by attempting to ensure that every undetectable fault has n incomplete tests with the smallest possible numbers of missing assignments, for a constant n ≥ 1. The incomplete tests are expected to contribute to the detection of detectable defects around the site of the undetectable fault. The computation of missing assignments for a test is performed in linear time by avoiding fault simulation and considering all the undetectable faults simultaneously. Experimental results demonstrate the extent to which a given test set can be improved without increasing the number of tests.