  This paper introduces the notion of Constrained Locating Arrays (CLAs),
mathematical objects which can be used for fault localization in software
testing. CLAs extend ordinary locating arrays to make them applicable to
testing of systems that have constraints on test parameters. Such constraints
are common in real-world systems; thus CLA enhances the applicability of
locating arrays to practical testing problems. The paper also proposes an
algorithm for constructing CLAs. Experimental results show that the proposed
algorithm scales to problems of practical sizes.
