Incremental Model-based Test Suite Reduction with Formal Concept Analysis

Abstract —Test scenarios can be derived based on some system models for requirements validation purposes. Model-based test suite reduction aims to provide a smaller set of test scenarios which can preserve the original test coverage with respect to some testing criteria. We are proposing to apply Formal Concept Analysis (FCA) in analyzing the association between a set of test scenarios and a set of transitions specified in a state machine model. By utilizing the properties of concept lattice, we are able to determine incrementally a minimal set of test scenarios with adequate test coverage. Keywords —Test Suite Reduction, Model-based Testing, State Machine Model, Formal Concept Analysis 1. I NTRODUCTION Test scenarios can be derived based on some system models for requirements validation pur-poses. Model-based testing [1, 16] refers to deriving a suite of test scenarios from a model that represents the behavior of a software system. In particular, state machine model has been widely used for this purpose in testing event-driven, reactive systems, and embedded software systems [1, 2]. State machine model can be used to specify the dynamic perspective of a system and its interactions with the users through sequences of transitions. The sequences of transitions can form a set of test scenarios for validation of functional requirements by test engineers and end users. However, since cycles in the state machine model may lead to an infinite number of test scenarios, exhaustive testing is usually not possible. Moreover, many test scenarios are part of some other test scenarios and thus lead to redundancy in the test suite. Model-based test suite reduction can be applied in this situation and derive a smaller set of test scenarios which still preserves the original test coverage with respect to some testing criteria. A default criterion of adequate testing with a state machine model is all-transition coverage criterion [1, 11, 16], which means each transition specified in the state machine model should be triggered at least once by executing the test scenarios. In this paper, we shall describe an incremental approach for reducing model-based test suite using Formal Concept Analysis (FCA) [6]. FCA is a mathematical technique for formulating concepts in terms of a set of formal objects and their associated formal attributes, and providing