Optimized Realization of Operational Requirements: A Goal-Oriented Approach

Goal-Oriented Requirements Engineering (GoRE) aims to capture the goals and strategies of key stakeholders during the initial phases of requirements engineering through the use of goal models. By employing goal-oriented modeling techniques, system requirements, particularly non-functional ones, can be analyzed from an operationalization perspective, enabling the evaluation of several design alternatives. However, the planning and scheduling of the retained operational tasks are deferred to subsequent stages, potentially affecting the soundness of the initially chosen goal-based strategy. In this paper, we propose a two-stage goal-oriented approach to generate an optimized realization plan, ensuring the fulfillment of both stakeholders' goals (addressed by the first stage) and operational objectives (addressed by the second stage), e.g., minimizing the weighted tardiness, minimizing the number of tardy tasks, minimizing the maximum lateness under precedence constraints, and minimizing the total completion time when task preemption is allowed. The resulting optimal sequence of operational tasks considers factors such as task dependencies, time constraints, and the impact of task order on the operational objective to ensure the most favorable outcome. Finally, we demonstrate the applicability of the proposed approach using an illustrative example describing the objectives of a marketing department and a real-world example of a mobile app that tracks school buses owned by a local university residential compound, with positive results on feasibility and validity.