Risk Modelling and Reasoning in Goal Models

In software engineering, risks are usually considered and analysed during, or even after, the design of the system. This approach can lead to the problem of accommodating necessary countermeasures in an existing design and possible to reconsider the initial requirements of the system. In this paper, we propose a goal-oriented approach for modelling and reasoning about risks at requirements level. Risks are introduced and analysed along the stakeholders' goals and countermeasures are imposed as part of the requirements of the system-to-be. The proposed framework is based on the Tropos methodology and extends the formal framework with new concepts and qualitative reasoning mechanisms to consider risks since the early phases of the requirements analysis. The risk analysis process is presented and illustrated with some experimental results.