Research And Implementation Of The Statistical Test Based On Cleanroom Software Engineering Case Tools

Cleanroom software engineering is an engineering technology that apply mathematics and statistics to developing software efficiently and economically. Cleanroom software testing-statistical testing based on usage models-is the application of statistical methods to software testing. In statistical testing,at first we must build the usage model which describes the usage profile of software, then random test cases were generated through usage model, finally quality metrics of software is evaluated according to statistical models.A usage model is the accurate description of software characteristics in use. It describes the usage profile of software with model. We can get many static statistics about a usage model through static analysis. These statistics are helpful to verification of usage model,deeper understanding of the use of software system and establishing test plan. Test case is a series of states and arcs that beginning at the initial state and ending at the terminate state. With the help of computer aided statistical testing tool,we can generate large amount of test cases easily. But,the problem is not the amount of test cases,it is how can we decide when to stop testing. Insufficient testing is irresponsible. Too sufficient testing results in resource wasting and is also irresponsible. The matter is how to determine what testing is insufficient and what testing is too sufficient. Statistical testing solves the problem by comparing testing chain with usage chain.Due to it's high efficiency and low costs,statistical testing is widely used at abroad and many computer aided statistical testing tool were developed such as JUMBL,ToolSET_Certify. With the basis of statistical testing theory,we developed a computer aided statistical testing tool "STToolkit" based on Java. It supports usage model building,statistics analysis and test cases generation. Besides,it can be used together with CaSoR(Computer aided Software Reliability tool) that it can invoke CaSoR to evaluate and predict the reliability of software. The STToolkit and CaSoR constitute an integrate software reliability engineering environment.