DEO: A Dynamic Event Order Strategy for t-way Sequence Covering Array Test Data Generation

Mohammed Issam Younis

doi:10.21123/bsj.2020.17.2.0575

Abstract

Sequence covering array (SCA) generation is an active research area in recent years. Unlike the sequence-less covering arrays (CA), the order of sequence varies in the test case generation process. This paper reviews the state-of-the-art of the SCA strategies, earlier works reported that finding a minimal size of a test suite is considered as an NP-Hard problem. In addition, most of the existing strategies for SCA generation have a high order of complexity due to the generation of all combinatorial interactions by adopting one-test-at-a-time fashion. Reducing the complexity by adopting one-parameter- at-a-time for SCA generation is a challenging process. In addition, this reduction facilitates the supporting for a higher strength of coverage. Motivated by such challenge, this paper proposes a novel SCA strategy called Dynamic Event Order (DEO), in which the test case generation is done using one-parameter-at-a-time fashion. The details of the DEO are presented with a step-by-step example to demonstrate the behavior and show the correctness of the proposed strategy. In addition, this paper makes a comparison with existing computational strategies. The practical results demonstrate that the proposed DEO strategy outperforms the existing strategies in term of minimal test size in most cases. Moreover, the significance of the DEO increases as the number of sequences increases and/ or the strength of coverage increases. Furthermore, the proposed DEO strategy succeeds to generate SCAs up to t=7. Finally, the DEO strategy succeeds to find new upper bounds for SCA. In fact, the proposed strategy can act as a research vehicle for variants future implementation.

Highlights

T-way test case generation strategies have been adopted as effective black-box testing strategies for many systems under test (SUT)
This paper extends the experiments to make an evaluation of Dynamic Event Order (DEO) and to facilitate the comparison against existing works
As shown in tabulated results, the size of Sequence covering array (SCA) in DEO can be started by t! and expanded logarithmically as the number of events increases

Summary

Introduction

T-way test case generation (termed combinatorial testing) strategies have been adopted as effective black-box testing strategies for many systems under test (SUT). EDIST-SA is a conceptual strategy that reported a lower bound SCA for t=3 and merely four input sequence to generate a SCA of size 6 (i.e., SCA (6, 3, 4)). // vertical process for event Ei while (π contains tuples) choose the first tuple from π and do the exhaustive search for missing events such that the combined test case (τ) covers the maximum number of tuples in π set; 22.

Results

Conclusion