Literature review: Combinatorial testing is one of the most interestingresearch topics. It is being enhanced from year to year over the past 20 year.
Initiatingfrom the proposal of different testing approaches(AETG, IPO, IPOG, IPO-s etc.) and applyingthem to different applications(Traffic collision avoidance system, Personal identity verification etc.), many works have been studied.
Few of themare mentioned in. this study.Mandl(1985) introduced Orthogonal Array Testing Strategy (OATS). If Influential factors of the systemare independent of each other then system is considered as orthogonal. All possible pairwiseinteractions are covered using “Orthogonal Latin Squares” to generate optimal test suite. Cohen et al. (1996, 1997)proposed an Automatic Efficient Test Generator (AETG) system.
Using greedyalgorithm test suite is built by repetitively adding one test at a time untilall the combinations of input domain are covered. They also described that the number of test casesgrow logarithmically as thenumber of parameters of a system increase.Lei and Tai (1998) proposed an In-Parameter-Order (IPO) strategy whichalso uses a greedy algorithm to build a pairwise test suite. It begins with thecombinations of first two input parameters and then covers the combinations of firstthree parameters and continues this way until combinations of all parameters arecovered. This strategyachieves lower order complexity than AETG strategy.Kuhnand Okum (2006) examined pseudo-exhaustive testing for software systems using real-world examples Traffic Collision Avoidance System (TCAS) and Personal Identity Verification (PIV) smart card.Leiet al.
(2007, 2008) of NationalInstitute of Standards andTechnology (NIST, a US organization) proposed an approach called IPOG (G isshort for Generalization). As IPO considersonly pairwise testing, but IPOGconsiders t-way testing where t is the strengthof coverage. They also introduced a tool called fireeye a t-way testingtool.Calvagnaand Gargantini (2009) proposed IPO-s approach which is a parameter-based heuristic algorithm for the construction of pairwise covering testsuites. Symmetries of covering arrays is used as basis to construct test suitesKuhn et al.
(2009) haveinvestigated on random vs combinatorialmethods for discrete event simulation of a grid computer networkTheir study explains that random generation of inputs for detecting deadlocks ,leadsto exhaustive testingbecause deadlock may occur