Making user-centred design common sense: striving for an unambiguous and communicative UCD process model

One challenge with regard to organisations and user-centred design (UCD) is to communicate the core substance of UCD to designers. For this purpose, we propose an outcome-driven, method-independent process model of UCD that was developed based on experiments in industrial settings. The model takes ISO 13407 and ISO 18529 as its base. The distinctive features of the new model are the identification of six UCD processes; the identification of process categories usability engineering and user interaction design; the definition of processes through outcomes; and the definition of the performance of the processes from three dimensions (quantity, quality, integration). We have used the model in the assessment of the performance of UCD processes --- the original purpose of the model --- and in project planning and training. Our experiments indicate that the model makes the essentials of UCD more comprehensible and easier to define. Furthermore, it responds to the challenge of integrating usability engineering and interaction design.