A new concept of in-vehicle Human-Machine Interface (HMI) was designed and evaluated with the joint effort of SEAT OEM (specifically, the Centro Técnico from Martorell, Barcelona) and the Human Factors Group within CIDAUT Research Centre (Fundación para la Investigación y Desarrollo en Transporte y Energía). As a result, both organisations contributed to a common paper presenting the UCD process followed for the design of such a system: “USER-CENTRED DESIGN APPROACH FOR AN INNOVATIVE HMI CONCEPT”, ATZ magazine, April 2012.
This innovative interface integrated diverse functionalities ranging from entertainment to communication (e.g. radio, multimedia or air-conditioning). In addition, it made use of a tactile interface to allow for introducing information and acting on the system through touch, profiting from the growing presence of tactile solutions in a wide range of everyday interactive products (e.g. smartphones, cash dispensers, navigation systems). This system is now included in the brand new SEAT León which has appeared on the market at the beginning of this year 2013.
For the development of the system, a User-Centred Design (UCD) methodology was followed by considering users as the centre of the process and involving them at the various stages of the product development cycle. In applying the UCD process, ISO 9241-210: 2010 – Ergonomics of the Human-System Interaction was considered, which establishes an iterative process aimed at achieving an optimum solution that satisfies user needs and system requirements in the most appropriate way. This standard provides requirements and recommendations for Human-Centred Design (HCD) principles and activities throughout the life cycle of computer-based interactive systems. For more details and ideas on HCD, see post on Reflections about UCD methodology.
The concept was initially designed and developed by SEAT and was then analysed in an iterative process based on experts and users evaluations conducted under the leadership of CIDAUT (specifically, me and my colleague Henar Vega were deeply involved in this project), in order to detect improvement needs that will result in a safe, comfort and usable system. During the whole process, there was a constant communication between both organisations to ensure an adequate progress within the project.
Thus, a complete usability study was conducted by CIDAUT in order to evaluate the interaction between drivers and the new SEAT HMI concept. The main areas of interest of this evaluation were: the philosophy, usability and intuitiveness of the new concept, interferences with the driving activity (perceived safety and distraction) and its aesthetics and graphic design. The evaluation was done in three main stages: experts analysis (heuristic principles considered on the basis of functional prototypes), users evaluation first round (first system implementation in a real car) and users evaluation second round (second implementation after fine-tuning based on results from the previous users evaluation). Heuristic principles were taken into consideration in the experts evaluation, in order to identify problematic aspects in the interaction with the system. The problems found were the basis for the definition of a group of tasks to be conducted by users in the subsequent usability tests. Specifically, the sample of users recruited for the tests was selected having as basis the drivers´ profile of the SEAT León, considering the gender and age distribution. In both users evaluations, the system was implemented in a real vehicle that was driven by participants in a test track in SEAT premises in Martorell (Barcelona). Various dedicated tools for data gathering and recording were used: experimenters’ templates, questionnaires and video recordings; providing an enriched set of data that could be globally analysed in order to draw relevant conclusions. The focus of the analysis of gathered data was on perceived usability, user uptake, workload, task completion times and errors rate.
To conclude, on the whole, the new HMI concept was assessed positively and its evaluation under real circumstances allowed the identification of specific areas of the interface that required revision or special attention. A significant improvement was already observed in the second round of usability tests, after some modifications were implemented in the system. At the end of the process, HMI recommendations and guidelines were formulated as improvement opportunities to be taken into account in the next phases of system development. This way, the applied UCD methodology demonstrates how a system can be optimised by following an iterative improvement process and involving potential users at the various stages of product development.
It is fascinating to see the results of this project in reality (new SEAT León)!
Although our involvement in the complete development process was quite concentrated in time and efforts, it was already possible to deepen in the reality of this kind of series design and development processes inside a big brand as the Volkswagen Group. We could acknowledge the restrictions imposed by the OEM and the selected technologies as well as the strict time constraints which usually characterise such kind of projects. It was a great experience to be part of the SEAT group and closely collaborate with them at their facilities, especially during such intensive weeks where the user tests were conducted.
UCD – Design and evaluation [Conducted at CIDAUT] 2010-2012