Measuring usability - balancing agility and formality : for stakeholders’ needs in software development

Sammanfattning: The main focus of the research presented in this thesis is a usability evaluation framework for mass market mobile devices, allowing measurement, comparison and presentation of the usability of hand held devices. The research has been a cooperation between an academic and an industrial partner, based on an action research approach, following the processes of Cooperative Method Development (CMD). It has used a case study approach, where the data has been analysed using techniques taken from grounded theory. Ethnography and participatory design have been central to both the research and the cooperation. With its basis in the evaluation framework, and its use of quantitative measurements and qualitative judgments framed by a focus on usability testing, this thesis contributes to aspects related to capturing real world usage in a continuously changing society, and supporting information needs in the process of building software. The evaluation framework can be used as a quality assurance tool in a wide perspective. It measures usability and the user experience, quickly and flexibly, and in so doing measures aspects of quality in use. It has been tested in a complex industrial development project and is a valuable and flexible tool that is easy for a usability expert to learn and use, to measure and help build quality on the customer’s terms. The results we have arrived at are of practical and theoretical interest within software engineering and the industrial telecom sphere. Several features and aspects of the evaluation framework are new and challenging. These are: its mix of qualitative and quantitative methods, allowing it to target many different stakeholders; experience in applying these methods in the technology-focused and rapidly changing mobile phone area; the challenge of addressing end users in a mass market; the challenge of finding presentation models for the many different stakeholders; the challenge of making sure the framework can be used in different stages in the industrial software development process. The framework is related to three areas of software engineering, Market Driven Requirements Engineering, Statistical Usage Testing, and Organisation and Product Together. Our work includes a discussion of the need for agility, which has not so far been focused upon and discussed within the area of software engineering and usability. The combination of factors included in the framework means that is unique in solving a number of the problems that are found in these different areas within software engineering, especially in a rapidly changing marketplace. We also contribute to the field, through the qualitative element of the evaluation framework, which is inspired by ethnography and participatory design. It thereby makes a contribution that can improve practice in the field of software engineering, and that contributes to the theoretical work that is being performed within these different research areas.