Aligning systems of systems engineering with goal-oriented approaches using the i* framework

Systems of Systems (SoS) are complex systems that result from the integration of a set of independent constituent systems — which are complex systems themselves — in order to achieve new functionalities and goals. The emerging interdisciplinary area of SoS and Systems of Systems Engineering (SoSE) is largely driven by stakeholders' goals and needs. In addition, Goal-Oriented Requirements Engineering (GORE) is a promising approach in the SoS context to be used in the identification, modelling and management of goals to be achieved by the overall SoS and as the starting point to requirements engineering of SoS. The i∗ goal-oriented approach has been used in the requirements specifications of monolithic systems, but has not been engaged so far in the derivation of requirements specifications in SoS. In this paper, we propose a novel approach by utilising the i∗ framework in developing a Goal-Oriented Requirements Engineering framework for Systems of Systems (SoSGORE). The approach drives the SoS Requirements Engineering (RE) process to explore, model and manage the goals of different stakeholders at two levels — the SoS-level goals and the constituent systems-level goals — in order to derive purposeful SoS requirements that are well-aligned with the users' goals and needs.