Internal Quality to External Quality: an Approach to Manage Conflicts

Abstract

Software Quality Attributes (QAs) can be categorised as either internal to the system as experienced by the developers or external to the system perceived by the end users. These QA categories have trade-off among them - an emphasis on internal QA may result in a compromise of an external QA. For example, there is a trade-off between maintainability and performance. Model-driven development approaches manage this trade-off and increase the degree of internal QA maintainability. In this work, we propose an ontology-based communication mechanism among software components to handle the trade-off. The approach increases the degree of internal QAs such as modifiability, maintainability, testability during the design and development phases without compromising the external QAs for the end users during the operation phase. We also evaluate a prototype system to validate the proposed approach using Software Architecture Analysis Method (SAAM). It is also easier to integrate into the software development life cycle as compared to existing model-driven approaches.