According to the descriptions above, on the basis of the test target, a complete test case should contain a special flow which consists of several steps, and every step involves several interface calls. The execution of interoperation is realized by inputting data into interfaces, and test verdict is set according to output data from interface, which has an influence on the execution in the next step. Once failure, the test system will terminate the execution of test case. Besides, according to the dependency relation at the interfaces, the output data from previous interface can be used as the input data to next interface. Fig. 5 shows the composition of test case.