Arshinder Kaur

In requirement analysis, goal models play an important role in assessing alternative design options of a software system. Many qualitative and quantitative goal reasoning approaches have been proposed for goal models such as Knowledge Acquisition in Automated Space (KAOS), Non- Functional Requirements (NFR), and Goal Oriented Requirement Language (GRL). However, for i∗ goal model only qualitative reasoning has been proposed in Requirement Engineering literature. The aim of this paper is to present a quantitative goal reasoning for i∗ goal model. The proposed approach was validated with case studies from existing literature and offers a guide in the decision process. To support the validation a simulation was developed in Visual C++.

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 Non-Functional 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.

Requirement analysis involves elicitation of suitable functions or operations and relevant data to support software. A requirement analyst examines different alternative options to decide on an optimal alternative option that benefits the stakeholders of the system. The decision making of alternative design option is complicated by the unavailable or incomplete and imprecise input data. Optimisation, an operation research technique, can be used as a method to solve this problem. The goal-oriented framework, such as i∗ is used to present social models for the analysis of a software system during the early phase of the requirement's engineering process. This paper aims to develop an optimisation model for the i∗ goal models, using multi-objective optimisation. The optimisation model aims to fully automate the goal analysis and to handle large goal models. A simulation for the proposed approach was developed by integrating Visual C++ with Matlab and was evaluated with case studies from the existing literature. The evaluation results show that the proposed approach is feasible and offers guidance in the decision making of alternative options.

Non-functional or quality requirements such as usability, integrity and security play a significant part in the success of a software system. Non-functional requirements have more impact on software systems than the functional requirements. In the early phase of requirements engineering, the various design options for the functional behaviour (also known as the goal) of a software system are analysed and the perfect ones are chosen. In the goal analysis process, the goals that contribute to the maximum satisfaction of the non-functional requirements (also known as the softgoals) have to be selected. Whilst there have been a number of approaches for goal analysis, this paper focuses on the softgoals based optimisation model to select goals for a given i∗ framework. This paper presents a multi-objective goal programming optimisation model to guide the goal analysis. A simulation for this approach was developed in Java Eclipse integrated with the IBM Cplex optimisation tool and evaluated with goal models such as Telemedicine, and Kids Youth counseling which were taken from the Requirements Engineering (RE) literature. The results of the evaluation show that the proposed optimal goal model approach is beneficial in the decision making of functional goals.

In requirements engineering (RE), goal models have been employed to represent stakeholder objectives and to decide on suitable functional (goal) requirements, from among the system requirements. A large number of goal analysis procedure both qualitative and quantitative have been proposed for the selection of alternative requirements and goal achievement. All of these procedures perform goal analysis by considering the non-functional (softgoals) requirements with objective function of same nature, such as the maximising nature. However, there are real-time situations, where stakeholder's requirements have opposing objectives/requirements (one to be maximized and other to be minimized). Hence, there is a need for a goal analysis procedure, which can select an alternative design option in situations where there is a goal model with goals of opposing objective functions. In this paper, the game theory (GT)-based approach has been proposed to perform the analysis of goals with opposing objective functions. A tool for the GT-based goal analysis has been developed in Java, integrated with the IBM Cplex optimization tool and evaluated with the adapted goal models from the existing RE literature. The results of this evaluation indicate that the proposed approach assists in the selection of alternatives in real-life situations where there are goals with opposing objective functions.