User experience goals in human-centred design of safety-critical systems

This dissertation studies the usage of user experience (UX) goals in early-stage human-centred design activities regarding safety-critical systems. The purpose of UX goals is to describe the desired user experiences to be focused on in the design work. The safety-critical technology environments of the empirical research of this thesis include rapid transit systems, container cranes in ports, command bridges of ships, and cars with driver-assistance systems. The empirical cases of the dissertation focus specifically on these four environments and their associated safety-critical systems’ human activity analysis, concept/prototype design, and early-phase evaluation from the UX goals perspective.

The studies in the cases have been conducted with different human factors and UX approaches, methods, and techniques. Core-Task Analysis is used as a key method in the cases with the analysis phase study reported in this dissertation. As analysis methods for the user evaluation studies’ results included in the thesis, the Usability Case approach, qualitative analysis of UX survey results, and quantitative statistical analysis of user acceptance survey results are used.

The specific research questions and results of this dissertation are related, firstly, to considering the value of experience design as part of safety-critical systems development in general. Secondly, the contribution of user activity analysis methods for the identification of UX goals is studied. Thirdly, the systematic specification, utilisation, and evaluation of UX goals in human-centred design of safety-critical systems is in the core focus of this thesis.

The results of this thesis indicate that UX goals bring additional value to the human-centred design work of safety-critical systems development. UX goals help in taking into account the experiences of users analytically in the concept or prototype design and evaluation stages. Moreover, the systematic use of UX goals makes the human-centred design and early-stage evaluations of safety-critical systems more target-driven, accurate, traceable, and measurable. Finally, UX goals’ appropriate usage in design can be seen to contribute to the meaningfulness, safety, effectiveness, and efficiency of human activity in safety-critical technology environments in general.