Recent software systems contain a lot of functions to provide various services. According to this tendency, software testing becomes more dicult than before and cost of testing increases so much, since many test items are required. In this paper, we propose and discuss such a new selective software testing method that is constructed from previous testing method by simplifying testing specification.

We have presented, in the previous work, a selective testing method to perform highly ecient software testing. The selective testing method has introduced an idea of functional priority testing and generated test items according to their functional priorities. Important functions with high priorities are tested in detail, and functions with low priorities are tested less intensively. As a result, additional cost for generating testing instructions becomes relatively high. In this paper, in order to reduce its cost, we change the way of giving information with respect to priorities. The new method gives the priority only rather than generating testing instructions to each test item, which makes the testing method quite simple and results in cost reduction. Except for this change, the new method is essentially the same as the previous method. We applied this new method to actual development of software tool and evaluated its effectiveness. From the result of the application experiment, we confirmed that many crucial faults can be detected by using the proposed method.