## Abstract

A covering array CA(N;t, k, v) is an N × k array with entries in {1,2,…, v}, for which everyN × t subarray contains each t-tuple of {1,2,…, v}^{t} among its rows. Covering arrays find application in interaction testing, including software and hardware testing, advanced materials development, and biological systems. A central question is to determine or bound CAN(t, k, v), the minimum number N of rows of a CA(N;t, k, v). The well known bound CAN(t, k, v) = O((t − 1)v^{t} log k) is not too far from being asymptotically optimal. Sensible relaxations of the covering requirement arise when (1) the set {1,2,…, v}^{t} need only be contained among the rows of at least(Formula presented.) of the N × t subarrays and (2) the rows of everyN × t subarray need only contain a (large) subset of {1,2,…, v}^{t}. In this paper, using probabilistic methods, significant improvements on the covering array upper bound are established for both relaxations, and for the conjunction of the two. In each case, a randomized algorithm constructs such arrays in expected polynomial time.

Original language | English (US) |
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Pages (from-to) | 1-20 |

Number of pages | 20 |

Journal | Theory of Computing Systems |

DOIs | |

State | Accepted/In press - May 27 2017 |

## Keywords

- Combinatorial design
- Covering arrays
- Orthogonal arrays
- Partial covering arrays
- Software interaction testing

## ASJC Scopus subject areas

- Theoretical Computer Science
- Computational Theory and Mathematics