## Abstract

Covering arrays with mixed alphabet sizes, or mixed covering arrays, are useful generalizations of covering arrays that are motivated by software and network testing. Suppose that there are k factors, and that the ith factor takes values or levels from a set G_{i} of size g_{i}. A run is an assignment of an admissible level to each factor. A mixed covering array, MCA(N;t,k,g_{1}g_{2}...g_{k}), is a collection of N runs such that for any t distinct factors, i_{1},i_{2},...,i_{t}, every t-tuple from G_{i1}×G_{i2}×. .×G_{it} occurs in factors i_{1},i_{2},...,i_{t} in at least one of the N runs. When g=g_{1}=g_{2}=...=g_{k}, an MCA(N;t,k,g_{1}g_{2}...g_{k}) is a CA(N;t,k,g). The mixed covering array number, denoted by MCAN(t,k,g1g2...gk), is the minimum N for which an MCA(N;t,k,g_{1}g_{2}...g_{k}) exists. In this paper, we focus on the constructions of mixed covering arrays of strength three. The numbers MCAN(3,k,g_{1}g_{2}...g_{k}) are determined for all cases with k∈{3,4} and for most cases with k∈;{5,6}.

Original language | English (US) |
---|---|

Pages (from-to) | 3640-3647 |

Number of pages | 8 |

Journal | Journal of Statistical Planning and Inference |

Volume | 141 |

Issue number | 11 |

DOIs | |

State | Published - Nov 1 2011 |

## Keywords

- Covering array
- Mixed covering array
- Orthogonal array

## ASJC Scopus subject areas

- Statistics and Probability
- Statistics, Probability and Uncertainty
- Applied Mathematics