A framework for maintaining software quality models

Given the increasing pervasiveness of software in our society and its growing complexity, it is essential to produce high software quality. The importance of satisfying customers' needs and keeping the software organization profitable have made the objective measurement and evaluation of software quality a fundamental task. A myriad of software quality models (QMs) intend to support product quality stakeholders in dealing with software quality. Most of these models can be assigned to one of two strategies for modeling software quality, namely fixed-model approaches and define-your-own-model approaches. The former usually specify a prescriptive set of quality characteristics or metrics, whereas the latter use methods to guide the experts in the derivation of customized QMs. The applicability of fixed models is generally limited to contexts similar to the one in which the model was developed, in contrast to define-your-own approaches, which require intensive ex-pert effort. A third option is represented by the so-called balanced QMs, which are based upon the idea of adapting a core model for specific domains and specific purposes and adjusting the resulting custom-tailored model to changes of its application environment. In order to be effective, quality modeling and quality models need, like any other technology employed in the context of software engineering, systematic maintenance. This means, in a broader sense, that a new technology needs to be introduced into an organization, integrated with the organization's processes, and continuously improved in response to changing environments. With respect to balanced quality models, maintenance refers to selecting a core model, adapting it to a particular context, and continuously improving the resulting custom-tailored model. Maintaining quality models should be as much reproducible as possible and should therefore be guided by a systematic process. This report presents a framework for maintaining quality models. The framework is based on the widely acknowledged quality improvement paradigm (QIP).