A Description Method Of Activity Flow In Use Case

With the unprecedented development of internet information technology, thedevelopment scale of modern application software expands greatly, and the function of it hasbecome more and more complicated. As a key step in software development, the softwarerequirement analysis phase has played a more and more important role in the whole softwareworking process. As a method initiated by scene description system, use case takes a keyposition in the software development process, which is especially crucial for the requirementanalysis phase of software. According to statistics, if mistakes or defects occur in therequirement analysis phase, a large cost input will be needed to rectify these mistakes ordefects, but the result may not be satisfactory. Some serious mistakes and defects in therequirement analysis phase may even lead to the failure of the whole development. So tosome extent, we may say that the success or failure of a software development project maydepend on the work done in requirement phase. Because of the different interpretation ofnatural language between software developer and client, the work in requirement phase issusceptible to divergence, leading to mistakes or defects. So a variety of description methodshas been adopted in order to avoid the ambiguity of natural language existence. For example,Z language is vastly adopted to describe requirement during practical situation. This methodwith its simplicity, conciseness is more manageable for developers, but it goes against tocommon client’s understanding and usage. In fact, the communication problem between thedeveloper and common client does not solved properly. From the previous argument, we canconclude that a feasible use case description could be implemented to clarify the need ofsoftware, helping common client and developer achieve a better understanding, reducing oravoiding the mistakes or defects occurred during software requirement analysis phase.This thesis analyses the current common requirement description method, and makes acomparison between them. Based on this comparison, a description method of activity flow inuse case will be proposed. The major research content consists of:1. Standardize the natural language: with the behavior unit concept, the softwarerequirement with natural language expression will be divided into three parts: User Input, Conditional, and System Output.2. Formatting: using behavioral slicing algorithm, the behavior unit of the previousstandardized natural language expression will be shown in unity with the formatting of man-machine interaction process. Compared with other description method, this requirementdescription method is close to natural language, being understandable and visually integrated.At the same time, it can avoid the ambiguity brought by natural language.3. Through specific experiment, this requirement analysis description method will beimplemented into the work of software demand. With this software requirement descriptionmethod, the mistakes and defects occurred during the requirement analysis phase will bereduced. Better understanding could be achieved between common client and developer, thusenhancing the working efficiency.In this thesis, the concept—behavior unit—was adopted. With the implementation ofbehavioral slicing algorithm in the demand of natural language description software, a unified,standardized, normalized, comprehensible software requirement description will be obtained.Through practical application, this method has relatively strong practicality to the extent ofenhancing the communication between common client and developer, and the workingefficiency of software development.