Covering arrays of higher strength from permutation vectors

A covering array CA (N; t, k, v) is an N x k array such that every N x t sub-array contains all t-tuples from v symbols at least once, where t is the strength of the array. Covering arrays are used to generate software test suites to cover all t-sets of component interactions. We introduce a combinatorial technique for their construction, focussing on covering arrays of strength 3 and 4. With a computer search, covering arrays with improved parameters have been found. (C) 2005 Wiley Periodicals, Inc.