Jiro Okayasu

A selective software testing method based on priorities assigned to functional modules

As software systems have been introduced to many advanced applications, the size of software systems increases so much. Simultaneously, the lifetime of software systems becomes very small and thus their development is required within a relatively short period. We propose a novel selective software testing method that aims to attain the requirement of short period development. The proposed method consists of 3 steps: assign priorities to functional modules (Step 1), derive a test specification (Step 2), and construct a test plan (Step 3) according to the priorities. In Step 1, for development of functional modules, we select both product and process properties to calculate priorities. Then, in Step 2, we generate detailed test items for each module according to its priority. Finally, in Step 3, we manage test resources including time and developers skill to attain the requirement. As a result of experimental application, we can show the superiority of the proposed testing method compared to the conventional testing method.

Elimination of crucial faults by a new selective testing method

Recent software systems contain a lot of functions to provide various services. According to this tendency, software testing becomes more difficult 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 efficient 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.

Generating test items for checking illegal behaviors in software testing

Even for electrical appliances, testing for illegal behaviors becomes difficult since the software system in an electrical appliance has already, become large in size. Actually the conventional method cannot generate sufficient test items for illegal behaviors. But testing illegal behaviors becomes more and more important, since the failure of electrical appliances would cause fatal effects on our daily life. We therefore propose a new method for generating appropriate test items to check illegal behaviors, which consists of the following steps: (1) describe software behavior using use case notation; (2) analyze illegal behavior by the deviation analysis technique; (3) construct a software fault tree using the above information; and (4) generate test items from the software fault tree. This paper also reports the experimental applications to actual development of an electrical appliance. The evaluation results identified that all necessary, test items for illegal behaviors are included in the resultant test items.

An approach to reverse quality assurance with data-oriented program analysis

The paper describes a quality assurance approach for source code to assure source code quality with less effort than conventional method. The paper introduces the data relation tracking method (DRTM) as a practical instance of data oriented program analysis, a key factor of our new quality assurance approach. DRTM helps comprehension of the source code by extracting the internal logic of the source code in declarative notation. An example and evaluation of DRTM for the C language is also described. The example shows that DRTM can deal in data structures and inter-data relations of any control structure. The evaluation shows that DRTM can extract the internal logic of the source code uniquely and that the extracted internal logic is useful for quality assurance of the source code.