Model-Based Trade-off Analysis of Non-Functional Requirements: An Automated UML-Based Approach

One common goal followed by software engineers is to deliver a product which satisfies the requirements of different stakeholders. Software requirements are generally categorized into functional and Non-Functional Requirements (NFRs). While NFRs may not be the main focus in developing some applications, there are systems and domains where the satisfaction of NFRs is even critical and one of the main factors which can determine the success or failure of the delivered product, notably in embedded systems. While the satisfaction of functional requirements can be decomposed and determined locally, NFRs are interconnected and have impacts on each other. For this reason, they cannot be considered in isolation and a careful balance and trade-off among them needs to be established. We provide a generic model-based approach to evaluate the satisfaction of NFRs taking into account their mutual impacts and dependencies. By providing indicators regarding the satisfaction level of NFRs in the system, the approach enables to compare different system design models and also identify parts of the system which can be good candidates for modification in order to achieve better satisfaction levels.