The Study Of Cost And Risk For The Confidence Software Test

The question of test automation cost and risk is always one of the hot spots for information and management research .Two main aspects are studied by domestic and foreign scholars, one is the test cost reducing through the test technology improvement, such as test suite reduction, test component reuse and so on, the other is test automation cost returning through return on investment, such as ROI analysis. These results have provided the important rationale for our research, but their methods have many deficiencies to the confidence software test, such as test suite reduction not considering the complex relation of test requirement, tests component reuse without quantifying description, ROI analysis not considering test maintenance cost.According to the special test requirement for the confidence software, this dissertation taking the test cost controled as the goal, studies the test technology improvement and the test process control by the theory of test and management. Its main research content is as follows:(1) Study on the test requirement reduction for the confidence software test. Confidence software including many credible attributes, its test is not only the function or the performance test, but also includes the software credible attributes and its environment test, therefore, the confidence software test is more comprehensive, complex, and its test cost is bigger, must reduce the test requirement. This dissertation presents some strategies to reduce the test requirement for confidence software. At first, considering credible attributes and McCall quality model, establishing assessment index for software credibility by AHP. With the instruction of assessment index, the first test requirement reduction is carried out by the classical statistical hypothesis, and then considering the complex relation of test requirement, the second reduction is also performed by greedy algorithm and heuristic algorithm. The example proves that two times reduction of test requirement will obtain test requirement suite that is complete and minimal redundancy, saving the test cost.(2) Study on the maintenance cost for the confidence software test automation. Automation regression test must be maintained repeatedly like its test object before testing, but the test automation maintenance cost is neglected frequently by tester. For example, Douglas Hoffman obtained the arbitrary conclusion without considering the test automation maintenance cost. As the same reason, Fewster and Graham also obtained the wrong conclusion. With the helping of Junit test tool and COCOMO II measurement method, this dissertation taking the DRAWING BOARD as example, introduces its revision process and corresponding test maintenance cost in detail, shows that automation regression test must be maintained repeatedly before testing, therefore, test automation maintenance cost is the important part of test investment. The research provides the automation risk will occur except that manual test is unable to carry on. A equation based on the Return On Investment ( ROI) model and COCOMO measurement method is presented. The maintenance cost is also taken into account. This equation proposes a concept of mean maintenance cost factor and precisely predicts risk occurrence threshold (mean maintenance cost factor threshold) .During the test automation process, test cost must be controlled if each time maintenance risk factor is bigger than its threshold. In addition, test component reusability is quantified by risk occurrence threshold. If threshold isα|- (0<α|-<1) ,then 1-α|- is test component minimal reusability,namely if test component reusability is at least original component 1-α|- times, the test risk will not occur.(4) Study on each time maintenance cost factor and strategies for the risk avoidance. Knowing risk occurrence threshold, we must estimate the value of each time maintenance cost factor. Comparing the value with its threshold, the possibility which the test automation risk occurred can be obtained. The factor which influences each time maintenance cost is studied in this dissertation. The possibility which indefinite risk factors get their value is also obtained by Delphi analysis, and then each time maintenance cost factor is determined by normal method. According to normal distribution, we can obtain the possibility for the test automation risk occurrence. At last a strategy for the risk avoidance is proposed by the sensitivity analysis, saving test cost.(5) Study on the stepts of using the cost control theory for confidence software test automation. Detailed stepts of using the cost control theory based on confidence software test automation are presented. The systematical construction and model of estimation and control cost for test automation are also studied in dissertation. Construction and model include all have been studied above, such as establishing assessment index (including consisitency checking) ,with the instruction of assessment index, the complex test requirement reduction twice, the model of estimation and control cost for test automation, sensitivity analysis of indefinite risk factor, the equation of risk control and so on. In the process of research, HIS is applied to demonstrate the effectiveness by these methods.This dissertation emphasizes on controlling cost and risk for test automation. It advances some new thinking routes and strategies for test automation on the ground of ancestor's work. The research is significant. It can consummate confidence software theory method, reduce the test cost, improve the software quality.