Integrating scenario-based usability engineering and agile software development

In recent years, agile software development methodologies such as extreme programming and SCRUM have emerged as one way to mitigate major risks of software development such as changing requirements, communication breakdowns and cost and scheduling overruns. These methodologies have become increasingly popular within the software development community and have been used in a variety of projects because they have helped in delivering software on-time that meets customer requirements. However, agile development methodologies—which focus on the design, implementation and maintenance of software, have marginalized the role of usability—which focuses on optimizing the interaction and information design of a system. This often results in software systems that meets functional requirements, but are difficult or frustrating to use. There is a need to develop a way to integrate usability into agile development practices without compromising the benefits they bring to software engineering. I have developed an approach to integrate extreme programming (XP)—a widely practiced agile design method with scenario-based design (SBD)—a well established usability engineering process. Key to this extreme scenario-based design (XSBD) approach is the central design record (CDR), a shared design representation I developed based on my work in rationale-based usability engineering. I hypothesize that this approach will enable the creation of agile development teams that include usability engineers who can work effectively with other stakeholders to develop usable software systems efficiently. This work will address three key issues: (1) How to satisfy the requirements from different stakeholders (specifically usability and software engineers) when they have different motivations, needs and concerns (2) How to maintain project velocity and a focus on the delivery of working software with the addition of usability practices and tools to the development process (3) How to develop & maintain a coherent interface and interaction architecture design in an agile development environment The successful integration of SBD and XP depends not only on shared design representations, but also on how they are used throughout the development cycle. Proposed efforts will focus on how the CDR can be used effectively in practice and will focus on how usability artifacts and results should be shared with agile developers and how project velocity can be maintained. This work will be validated with a comprehensive case study conducted at Meridium, Inc and results will be disseminated through journal and conference paper submissions and workshops at leading agile and usability venues. Design principles and practices that are developed will be broadly applicable to the agile community and will also contribute to and make connections with the HCI research community.