Abstract: In the field of requirements engineering,the subject based on i* framework including the strategy dependency model and strategy rationale model has become one of the most commonly used tools in the early requirements modeling and analysis．At the same time,many research works focus on the development of i* modeling framework editing tools．However,the existing tools often provide only basic functions,such as model diagram editing,storage,etc.,which do not satisfy the requirements that we need to visualize the modeling results of requirements text in our requirements engineering group,and also provide the editing storage and the automatic layout．Therefore,it is needed to develop a new tool based on i* framework. Firstly,this thesis investigated and surveyed the well-known modeling tools and analyzed the basic functions of them,as well as the shortcomings．Then,on this basis,we proposed and designed the supplement functions of our new tool,and introduced the layout problems of i* framework,as well as detailedly described the implementation of its automatic layout algorithm．Finally,we presented the detailed design of the visualization tool. Based on the proposed tool,we carried out experiments on the requirements text modeling and the model editing functions,and also compared them with the corresponding functions of well-known modeling tools to demonstrate the features of our tool.

Key words: i* framework,Visualization tool,Automatic layout,Strategy dependency,Strategy rationale