A QOS Ontology-Based Component Selection

In the component-based software development, the selection step is very important. It consists of searchingand selecting appropriate software components from a set of candidate components in order to satisfy thedeveloper-specific requirements. In the selection process, both functional and non-functional requirementsare generally considered. In this paper, we focus only on the QoS, a subset of non-functionalcharacteristics, in order to determine the best components for selection. The component selection based onthe QoS is a hard task due to the QoS descriptions heterogeneity. Thus, we propose a QoS ontology whichprovides a formal, a common and an explicit description of the software components QoS. We use thisontology in order to semantically select relevant components based on the QoS specified by the developer.Our selection process is performed in two steps: (1) a QoS matching process that uses the relationsbetween QoS concepts to pre-select candidate components. Each candidate component is matched againstthe developer’s request and (2) a component ranking process that uses the QoS values to determine the bestcomponents for selection from the pre-selected components. The algorithms of QoS matching andcomponent ranking are then presented and experimented in the domain of multimedia components.