Improved Strength Four Covering Arrays with Three Symbols

Soumen Maity, Yasmeen Akhtar, Reshma C. Chandrasekharan, Charles Colbourn

Research output: Contribution to journalArticle

1 Scopus citations


A covering array t-CA(n, k, g), of size n, strength t, degree k, and order g, is a (Formula presented.) array on g symbols such that every (Formula presented.) sub-array contains every (Formula presented.) column on g symbols at least once. Covering arrays have been studied for their applications to software testing, hardware testing, drug screening, and in areas where interactions of multiple parameters are to be tested. In this paper, we present an algebraic construction that improves many of the best known upper bounds on n for covering arrays 4-CA(n, k, 3). The t-coverage of a testing array (Formula presented.) is the number of distinct t-tuples contained in the column vectors of (Formula presented.) divided by the total number of t-tuples. If the testing array is a covering array of strength t, its t-coverage is 100%. The covering arrays with budget constraints problem is the problem of constructing a testing array of size at most n having largest possible coverage, given values of t, k, g and n. This paper also presents several testing arrays with high 4-coverage.

Original languageEnglish (US)
Pages (from-to)1-17
Number of pages17
JournalGraphs and Combinatorics
StateAccepted/In press - Dec 15 2017



  • Coverage
  • Covering arrays
  • Projective general linear group
  • Software testing

ASJC Scopus subject areas

  • Theoretical Computer Science
  • Discrete Mathematics and Combinatorics

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