Reasoning about Goal Satisfaction for Early Requirements Engineering in the i* Framework using Inter-Actor Dependency

In the software development cycle, requirements engineering plays a major role in the success of a software system. In early requirement engineering, various alternative design options for software are explored and the best ones are selected. The requirements analyst uses goal models to analyse different design alternatives. Goal models like the i*, and Tropos include inter-actor dependencies where an actor depends on other actors for its goal accomplishment. However, goal models like NonFunctional Requirements(NFR), Knowledge Acquisition in Automated Space (KAOS) do not include these type of inter-actor dependencies. Whilst there have been a number of both qualitative and quantitative proposed approaches to analysing goal models without using inter-actor dependency, this paper presents an approach to the automate analysis of goals using inter-actor dependencies and fuzzy concepts. A simulation for the proposed approach was developed in Visual C++ and was evaluated with case studies from the existing literature. The evaluation results show that the proposed approach is feasible and offers a guidance in the decision making of alternative options.