Context. Agile methods are increasingly being used by companies, to develop digital products and services faster and more effectively. Today's users not only demand products that are easy to use, but also products with a high User Experience (UX). Agile methods themselves do not directly support the development of products with a good user experience. In combination with UX activities, it is potentially possible to develop a good UX.
Objective. The objective of this PhD thesis is to develop a UX Lifecycle, to manage the user experience in the context of Agile methods. With this UX Lifecycle, Agile teams can manage the UX of their product, in a targeted way.
Method. We developed the UX Lifecycle step by step, according to the Design Science Research Methodology. First, we conducted a Structured Literature Review (SLR) to determine the state of the art of UX management. The result of the SLR concludes in a GAP analysis. On this basis, we derived requirements for UX management. These requirements were then implemented in the UX Lifecycle. In developing the UX Lifecycle, we developed additional methods (UX Poker, UEQ KPI, and IPA), to be used when deploying the UX Lifecycle. Each of these methods has been validated in studies, with a total of 497 respondents from three countries (Germany, England, and Spain). Finally, we validated the UX Lifecycle, as a whole, with a Delphi study, with a total of 24 international experts from four countries (Germany, Argentina, Spain, and Poland).
Results. The iterative UX Lifecycle (Figure 1) consists of five steps: Initial Step 0 ‘Preparation’, Step 1 ‘UX Poker’ (before development/Estimated UX), Step 2 ‘Evaluate Prototype’ (during development/Probable UX), Step 3 ‘Evaluate Product Increment’ (after development/Implemented UX), and a subsequent Step 4 ‘UX Retrospective’.
With its five steps, the UX Lifecycle provides the structure for continuously measuring and evaluating the UX, in the various phases. This makes it possible to develop the UX in a targeted manner, and to check it permanently. In addition, we have developed the UX Poker method. With this method, the User Experience can be determined by the Agile team, in the early phases of development. The evaluation study of UX Poker has indicated that UX Poker can be used to estimate the UX for user stories. In addition, UX Poker inspires a discussion about UX, that results in a common understanding of the UX of the product. To interpret the results from the evaluation of a prototype and product increment, we developed or derived the User Experience Questionnaire KPI and Importance-Performance Analysis. In a first study, we were able to successfully apply the two methods and, in combination with established UEQ methods, derive recommendations for action, regarding the improvement of the UX. This would not have been possible without their use. The results of the Delphi study, to validate the UX Lifecycle, reached consensus after two rounds. The results of the evaluation and the comments lead to the conclusion, that the UX Lifecycle has a sufficiently positive effect on UX management.
Conclusion. The goal-oriented focus on UX factors and their improvement, as propagated in the UX Lifecycle, are a good way of implementing UX management in a goal-oriented manner. By comparing the results from UX Poker, the evaluation of the prototype, and product increment, the Agile team can learn more about developing a better UX, within a UX retrospective. The UX Lifecycle will have a positive effect on UX management. The use of individual components of the UX Lifecycle, such as UX Poker or Importance-Performance Analysis, already helps an Agile team to improve the user experience. But only in combination with the UX Lifecycle and the individual methods and approaches presented in this PhD thesis, is a management of the user experience in a targeted manner possible, in our view. This was the initial idea of this PhD thesis, which we are convinced we could implement.