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- Grindal, Mats, et al.
(författare)
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An Evaluation of Combination Strategies for Test Case Selection
- 2006
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Ingår i: Empirical Software Engineering. - : Springer. - 1382-3256 .- 1573-7616. ; 11:4, s. 583-611
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Tidskriftsartikel (refereegranskat)abstract
- This paper presents results from a comparative evaluation of five combination strategies. Combination strategies are test case selection methods that combine “interesting” values of the input parameters of a test subject to form test cases. This research comparatively evaluated five combination strategies; the All Combination strategy (AC), the Each Choice strategy (EC), the Base Choice strategy (BC), Orthogonal Arrays (OA) and the algorithm from the Automatic Efficient Test Generator (AETG). AC satisfies n-wise coverage, EC and BC satisfy 1-wise coverage, and OA and AETG satisfy pair-wise coverage. The All Combinations strategy was used as a “gold standard” strategy; it subsumes the others but is usually too expensive for practical use. The others were used in an experiment that used five programs seeded with 128 faults. The combination strategies were evaluated with respect to the number of test cases, the number of faults found, failure size, and number of decisions covered. The strategy that requires the least number of tests, Each Choice, found the smallest number of faults. Although the Base Choice strategy requires fewer test cases than Orthogonal Arrays and AETG, it found as many faults. Analysis also shows some properties of the combination strategies that appear significant. The two most important results are that the Each Choice strategy is unpredictable in terms of which faults will be revealed, possibly indicating that faults are found by chance, and that the Base Choice and the pair-wise combination strategies to some extent target different types of faults.
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| 2. |
- Lindström, Birgitta, 1958-
(författare)
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Testability of Dynamic Real-Time Systems
- 2009
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This dissertation concerns testability of event-triggered real-time systems. Real-time systems are known to be hard to test because they are required to function correct both with respect to what the system does and when it does it. An event-triggered real-time system is directly controlled by the events that occur in the environment, as opposed to a time-triggered system, which behavior with respect to when the system does something is constrained, and therefore more predictable. The focus in this dissertation is the behavior in the time domain and it is shown how testability is affected by some factors when the system is tested for timeliness.This dissertation presents a survey of research that focuses on software testability and testability of real-time systems. The survey motivates both the view of testability taken in this dissertation and the metric that is chosen to measure testability in an experiment. We define a method to generate sets of traces from a model by using a meta algorithm on top of a model checker. Defining such a method is a necessary step to perform the experiment. However, the trace sets generated by this method can also be used by test strategies that are based on orderings, for example execution orders.An experimental study is presented in detail. The experiment investigates how testability of an event-triggered real-time system is affected by some constraining properties of the execution environment. The experiment investigates the effect on testability from three different constraints regarding preemptions, observations and process instances. All of these constraints were claimed in previous work to be significant factors for the level of testability. Our results support the claim for the first two of the constraints while the third constraint shows no impact on the level of testability.Finally, this dissertation discusses the effect on the event-triggered semantics when the constraints are applied on the execution environment. The result from this discussion is that the first two constraints do not change the semantics while the third one does. This result indicates that a constraint on the number of process instances might be less useful for some event-triggered real-time systems.
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