Bridging the Gap between the Quality Requirements and Implementation

There is an increasing need for providing software products with different quality attributes. Especially in the context of product families each customer group may demand different quality attributes from a product while functional requirements remain the same. Although there are many languages for expressing quality requirements, still there is a gap between the requirements specification and their implementation. In this paper, the means for expressing quality attributes and affecting the qualities in software systems are scrutinized and illustrated in a laboratory case of stream-oriented computing system. We take a domain-specific modelling approach in order to express qualities in software models explicitly. As a result, there is a comprehensive link between the quality attributes in a software system and the quality requirements. In addition, modifying a software system according to the quality requirements is facilitated.