A Hybrid Approach for Multi-Attribute QoS Optimisation in Component-Based Software Systems

Abstract. Design decisions for complex, component-based systems impact multiple quality of service (QoS) properties. Often, means to improve one quality property deteriorate another one. In this scenario, selecting a good solution with respect to a single quality attribute can lead to unacceptable results with respect to the other qual-ity attributes. A promising way to deal with this problem is to exploit multi-objective optimization where the objectives represent different quality attributes. The aim of these techniques is to devise a set of solutions, each of which assures a trade-off be-tween the conflicting qualities. To automate this task, this paper proposes a combined use of analytical optimization techniques and evolutionary algorithms to efficiently identify a significant set of design alternatives, from which an architecture that best fits the different quality objectives can be selected. The proposed approach can lead both to a reduction of development costs and to an improvement of the quality of the final system. We demonstrate the use of this approach on a simple case study.