Optimal Reasoning of Opposing Non-functional Requirements based on Game Theory

Goal-Oriented Requirement Engineering is a modeling technique that represents software system requirements using goals as goal models. In a competitive environment, these requirements may have opposing objectives. Therefore, there is a requirement for a goal reasoning method, which offers an alternative design option that achieves the opposing objectives of inter-dependent actors. In this paper, a multi-objective zero-sum game theory-based approach is applied for choosing an optimum strategy for dependent actors in the i* goal model. By integrating Java with IBM CPLEX optimisation tool, a simulation model based on the proposed method was developed. A successful evaluation was performed on case studies from the existing literature. Results indicate that the developed simulation model helps users to choose an optimal design option feasible in real-time competitive environments

AHP based Optimal Reasoning of Non-functional Requirements in the i∗ Goal Model

Goal-Oriented Requirements Engineering (GORE) has been found to be a valuable tool in the early stages of requirements engineering. GORE plays a vital role in requirements analysis like alternative design/ goal selection during decision-making. The decision-making process of alternative design/ goal selection is performed to assess the practicability and value of alternative approaches towards quality goals. Majority of the GORE models manage alternative selection based on qualitative approach, which is extremely coarse-grained, making it impossible for separating two alternatives. A few works are based on quantitative alternative selection, yet this does not provide a consistent judgement on decision-making. In this paper, Analytic Hierarchy Process (AHP) is modified to deal with the evaluation of selecting the alternative strategies of inter-dependent actors of i∗ goal model. The proposed approach calculates the contribution degrees of alternatives to the fulfilment of top softgoals. It is then integrated with the normalized relative priority values of top softgoals. The result of integration helps to evaluate the alternative options based on the requirements problem against each other. To clarify the proposed approach, a simple telemedicine system is considered in this paper

Reasoning of Competitive Non-Functional Requirements in Agent-Based Models

During the decision-making process in real-time competitive environments, there is a need to perform concurrent optimisation of multiple competitive objectives to select an optimal design decision for interdependent stakeholders. To handle such issues, this thesis successfully assimilates the goal-oriented requirements-engineering knowledge with analytical decision-making approaches to facilitate reasoning and analysis by encouraging stakeholders’ involvement. This leads to optimal decisions with domain knowledge improvement in the agent-based i*-goal model by balancing multiple conflicting non-functional requirements reciprocally

Optimal goal programming of softgoals in goal-oriented requirements engineering

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