User-centred design of smart products

In and around our homes and offices we are confronted with a rapidly increasing variety of smart products, such as microwave ovens, video-recorders, facsimile equipment, and automatic teller machines. For casual users, particularly, the interaction with these modern electronic products is potentially difficult as, for commercial reasons, most of them integrate multiple and complex functions, with dozens of features, while lacking user interfaces that foster a coherent conceptual model that makes functionality apparent and comprehensible. Adherence to an iterative, user-centred design process, instead of the common, technology and market driven one, leads to more useful and usable products. These products have a reduced functionality that matches real user needs and preferences. This paper describes the process of user-centred design as it has been developed over the past 25 years at the Faculty of Industrial Design Engineering of Delft University of Technology. It focuses on the methods for extracting design oriented information from and about the prospective users in the early phases of idea generation, and evaluation of the process. It is in these phases that the major decisions with respect to functionality and basic principles of interaction are made. It appears that small-scale qualitative user studies and unstructured walkthrough methods with experts stand the best chance of being adopted here. The timely availability of adequate representations of the design concepts in question, such as sketches and models, is essential, not only to involve users and experts effectively, but also to enhance communication between members of the multidisciplinary design team. It is concluded that good user-centred design shortens overall development time and costs by reducing the number of expensive changes required late in the design process, and results in better quality products. This is very important in a market that, understandably, is becoming more discriminating, both with respect to usefulness and usability.