Defence of dissertation in the field of Software Engineering, Varvana Myllärniemi, M.Sc.(Tech.)

Quality Attribute Variability in Software Product Lines: Varying Performance and Security Purposefully

Varvana Myllärniemi, M.Sc.(Tech.), will defend the dissertation “Quality Attribute Variability in Software Product Lines: Varying Performance and Security Purposefully” on 6 November 2015 at 12 noon in Aalto University, School of Science, lecture hall T2, Konemiehentie 2, Espoo. In the dissertation "Quality Attribute Variability in Software Product Lines: Varying Performance and Security Purposefully” the aim was to study why and how to vary quality attributes purposefully in a software product line. The results highlight that when making decisions about quality attribute variability, it is important to understand both the customers as well as the architecture design.

Quality attributes, such as performance, security and reliability, play a significant role in satisfying the stakeholders' needs. However, it is not always easy to achieve the desired quality in software products, perhaps because software engineering practices have traditionally focused on functional features. It is even more challenging to produce several versions of the same product with purposefully different quality. For example, some customer segments are offered a mobile game with top notch graphics but large resource consumption, whereas some customers need a game that runs smoothly on a weaker mobile device.

This dissertation studied why and how to vary quality attributes purposefully in a software product line. We focused on performance and security as quality attributes. The results highlight that when making decisions about quality attribute variability, it is important to understand both the customers as well as the architecture design. Essentially, quality attributes are varied to serve the differences in the customer needs and characteristics, but at the same time architecture design and operating environment constraints often motivate the decision to vary. The company must decide how to communicate the quality differences so that the customers can select between the product versions. It is also challenging to design the shared software architecture for the product versions and to ensure the desired quality differences between the products.

Opponent: Professor Ivica Crnkovic, Chalmers University of Technology, Sweden

Custos: Professor Marjo Kauppinen, Aalto University School of Science, Department of Computer Science

Electronic dissertation: https://aaltodoc.aalto.fi/handle/123456789/18025

School of Science, electronic dissertations: https://aaltodoc.aalto.fi/handle/123456789/52