Randomized postoptimization of covering arrays

Peyman Nayeri, Charles Colbourn, Goran Konjevod

Research output: Chapter in Book/Report/Conference proceedingConference contribution

17 Scopus citations


The construction of covering arrays with the fewest rows remains a challenging problem. Most computational and recursive constructions result in extensive repetition of coverage. While some is necessary, some is not. By reducing the repeated coverage, metaheuristic search techniques typically outperform simpler computational methods, but they have been applied in a limited set of cases. Time constraints often prevent them from finding an array of competitive size. We examine a different approach. Having used a simple computation or construction to find a covering array, we employ a postoptimization technique that repeatedly adjusts the array in order to (sometimes) reduce its number of rows. At every stage the array retains full coverage. We demonstrate its value on a collection of previously best known arrays by eliminating, in some cases, 10% of their rows. In the well-studied case of strength two with twenty factors having ten values each, postoptimization produces a covering array with only 162 rows, improving on a wide variety of computational and combinatorial methods. We identify certain important features of covering arrays for which postoptimization is successful.

Original languageEnglish (US)
Title of host publicationCombinatorial Algorithms - 20th International Workshop, IWOCA 2009, Revised Selected Papers
Number of pages12
StatePublished - 2009
Event20th International Workshop on Combinatorial Algorithms, IWOCA 2009 - Hradec nad Moravici, Czech Republic
Duration: Jun 28 2009Jul 2 2009

Publication series

NameLecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
Volume5874 LNCS
ISSN (Print)0302-9743
ISSN (Electronic)1611-3349


Other20th International Workshop on Combinatorial Algorithms, IWOCA 2009
Country/TerritoryCzech Republic
CityHradec nad Moravici

ASJC Scopus subject areas

  • Theoretical Computer Science
  • General Computer Science


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