Meaning Of Usability And User Experience In HMI Design

Interview With Franz Koller

Franz Koller is the founder and Managing Director of User Interface Design GmbH (UID).
The graduate computer scientist previously led the market strategy team Interactive Products at the Fraunhofer IAO and was a research assistant and project manager at the University of Stuttgart. Franz Koller has over 30 years of experience in designing human-machine interaction. He advises well-known customers in the consumer, enterprise and industry sectors. Franz Koller is a member of the board of the „Software & Digitalization“ Association of the VDMA.


Smart HMI: What’s the difference between Usability and User Experience (UX)?
Franz: Many use usability and user experience synonymously. However, both terms highlight different aspects of human-machine interaction.

Usability is a measure of the degree how easily users interact with a product. With user-friendly solutions, users reach their goals and tasks faster and are happier when using them. Mistakes and frustration are avoided or reduced.

The term User Experience goes one step further: user experience focuses on the positive feelings during the usage. Users experience the product positively when it meets their basic psychological needs, such as: Does this raise the motivation to use the product more
intensively, creatively and productively (Variety)? Can the user identify with the product (Significance)? Does the user feel connected to others through the product (Connection)? Can he get to know something new or experience himself as capable and effective (Contribution)?

Usability is about avoiding usage problems and negative emotions such as frustration and annoyance through user-centered design. User Experience Design aims to create systematically positive or even personally meaningful user experiences. That’s why User Experience is not just relevant to consumer products. Positive user experience can also be achieved in the work context.

Smart HMI: Is there a specific way to achieve good usability or positive UX?
Franz: The Human Centered Design Process is an established design process for user-oriented interactive systems. The aim of the iterative process is to integrate the targeted user groups into the design process and to consider their goals and needs.

The design takes place in four phases. The first phase is for ANALYSIS. In this phase, UX experts analyze users‘ goals, needs and tasks and their respective usage environment. From the results, they derive requirements for the HMI. In the second phase the DESIGN takes place. Here, UX experts develop the basic layout as well as the navigation and interaction concepts that meet the requirements of the analysis. The third phase makes the concepts of the second phase EXPERIENCED, for example in the form of hand sketches or interactive prototypes. This allows UX experts to simulate usage processes early on and evaluate their impact on the user experience. In the final phase, the UX experts TEST the developed solutions with representative users. The generated feedback should flow back into the design process in order to generate optimal solutions in an iterative procedure.

Important in this process is that short-cycle iterations are possible and can be jumped back to a phase at any time.

Smart HMI: Why should an industrial HMI create enthusiasm to users?
Franz: In engineering, the focus is often on intuitive operation and the user experience isn’t taken into consideration in a larger scale. But it has the potential to cause positive feelings, increase motivation in the long term, and create a positive working environment. In addition, users transfer their experience with consumer devices such as smartphones to the world of work. The expectations arising from this consumerization set the benchmark for industrial interfaces. Technically and high-quality products alone are no longer sufficient in a globalized competition to achieve long-term customer loyalty. The user experience plays an important role and decides on the success or failure of a product.

The study „Emotional Design for HMIs“ of the Hochschule der Medien (Stuttgart) and User Interface Design GmbH shows how important positive user experiences are at work. Accordingly, it is above all creative and instructive activities that influence the well-being and thus the efficiency of the employees. Today, however, workflows and processes in production plants are highly automated and the employees are essentially busy monitoring these automated processes. Interactive products and services have the task of resolving this contradiction: they should counteract purely supervising activities in the workplace, strengthen one’s own competence experience and promote cooperation with colleagues.

Smart HMI: Why is investment in usability or user experience worthwhile in HMI design? Franz: Usability and user experience benefit users and operating companies alike. There are not only soft factors such as happier customers or stronger brand loyalty. A user-centered HMI design brings clear economic benefits: With a user-centered design, companies secure their investments in product development. By getting users involved in development right from the beginning, companies ensure that future users will enjoy the product and use it. Even in times of agile development processes, every euro invested in early user feedback pays off many times over if expensive corrections during or after implementation are avoided.

Users are more effective and efficient, if a product is tailored to their needs, tasks, and work environment. We have customers who have been proven to increase user productivity and efficiency by 20 to 30 percent through usability measures.

Good usability can reduce the cost of training and further education by more than half. Because intuitively operable products are quick and easy to learn. For example, they provide users with a quick overview and access to all relevant information and functions. A consistent interaction and a consistent design across entire product families also make it easier to work in. Users can transfer their operating knowledge from one machine to another. In addition, usability and user experience have a significant impact on the brand image because the user interface is the face of a product. The user experiences the product through it.

Smart HMI: Thank you for the interview.