Formatted Demand For Natural Language Description

With enhancing the size and complexity of software, requirements grow into the critical stage in the entire project of software development, and people pay more and more attention on its importance. The recent studies indicate that most defects of software emerge in the phase of requirements. With the process of the software development, it costs much more to make up these defects, even leads to a failure of the whole project. The defects arise in this phase primarily due to the discrepant understanding of requirements between users and developers, as the natural language specification is prone to cause ambiguities, and the expression of formal specification language such as Z language appears to be abstract and intricate. So it is necessary to choose the appropriate method to make the requirements definite for the users and developers and minify the mistakes and defects in the phase of requirements.The thesis introduces a methodology of requirements specification based on natural language by analyzing and studying available methodologies. The key contributions of this thesis are as follows:(1) We mark each interactive step in requirements as user input, system process and system output according to the concept of units of behavior in order to standardize the requirements specification in natural language.(2) We formalize the requirement with the method of behavioral slicing by analyzing the process of interaction and the interactive behavior between the users and the system. As a result, we get a formalized output with a unified structure. The method of expression retains the readability and comprehensibility of natural language, and ensures the accuracy and completeness of requirements specification.(3) In the experimental environment, we analysis of user requirements with behavioral slicing. The results illustrated that the method helps to eliminate the mistakes and defects at the requirements phase, as well as improve the productivity of the development of software, which provides a sound access for the users and developers to communicate the requirements.In this thesis we combine the concept of units of behavior and the methodology of requirements specification based on natural language. By using behavioral slicing, we get a uniform, standardized requirement description and validate the reduction of differences in requirements and the efficiency of software development.