What is usability?
Usability refers to the suitability for use and user-friendliness of an interactive system. Its quality is primarily measured by how easily and efficiently users can achieve their goals. As a central sub-area of user experience (UX), usability significantly influences the acceptance and probability of success of a product.
Usability: definition and key criteria
A binding definition of usability is provided by the standard DIN EN ISO 9241-11 “Usability: Terms and concepts”. It is part of an international series of standards on the ergonomics of human-system interaction and states:
“Usability is the extent to which a system, product or service can be used by specific users in a specific context of use in order to achieve specific goals effectively, efficiently and satisfactorily.”
Which systems are meant?
In summary, “system, product or service” refers to all interactive systems and services that enable two-way communication between humans and machines. The interaction takes place through the user’s input and the system’s reactions.
Interactive systems can be digital media and software applications as well as physical hardware components and devices, e.g:
- Websites and apps
- Computer programs
- CRM and ERP systems
- PCs, smartphones and tablets
- Voice assistants
- Smart home systems
- medical devices
- Cash or ticket machines
Which criteria are decisive for usability?
The ISO 9241-11 standard emphasizes three criteria that are important for the objective assessment of suitability for use:
Effectiveness
The question here is: How well do users achieve their goals?
In an online store, for example, effectiveness is high when a user can easily find the desired products and complete the purchase without additional support.
Efficiency
How quickly and resource-efficiently can users reach their destination?
The use of an ERP system, for example, is efficient when employees perform their tasks with as little input and time as possible.
Satisfaction
How pleasant do users find the interaction?
Even if a website is effective and efficient to use, it can still leave a negative impression. If, for example, important information on shipping costs or data protection guidelines is missing, this will arouse mistrust.
In addition, supplementary criteria must be observed, such as
Learnability
How easy is it for new users to learn the functions of an interactive system?
User-friendly elements such as self-explanatory navigation and intelligent assistance systems reduce the barriers to entry.
Error rate
How often do errors occur and how well does the system support users in troubleshooting?
Helpful error messages or undo functions, for example, provide a quick remedy.
Memorability
How well can users find their way around even after a long break?
Above all, a consistent design ensures that users quickly find their way around.
Accessibility
How well can people with different physical or cognitive impairments use a system?
A design with accessibility features such as screen reader compatibility and adjustable font size ensures that content is equally accessible to all users.
What is the difference between usability and user experience?
The terms usability and user experience (UX) are often used as synonyms. However, this is not correct. Usability is only one component of user experience. It focuses exclusively on the experiences that users have with an interactive system while they are using it. A system with high usability can be operated intuitively and enables goals to be achieved quickly.
User experience, on the other hand, encompasses a user’s entire perception of a product and goes far beyond mere usability. It begins with the first impression and ends with the memories of the user experience. It therefore also takes into account the subjective expectations before use and the experiences after use.
Accordingly, a high level of usability alone cannot guarantee a good user experience. If the ordering process in an online store can be completed quickly and in a self-explanatory manner, good user-friendliness is guaranteed. However, if the delivery time is unusually long and the customer service is extremely unfriendly, the overall user experience will ultimately be negative.
Why is good usability important?
The usability of an interactive product is very important for both users and manufacturers. After all, good usability not only leads to high user acceptance and efficient processes on the customer side. It also determines customer loyalty and therefore the long-term success of a company.
The advantages of good usability at a glance
Higher customer satisfaction and loyalty
With intuitive applications and devices, users are able to successfully complete their tasks without frustration. This makes them feel competent and happy to use the product. As a result, they associate the provider with a pleasant experience and remain loyal to the brand in the future.
Less time required
Thanks to good usability, users can complete their tasks more quickly. Clear structures and well thought-out processes help them to reach their goal without detours. At the end of the day, companies not only save time but also money thanks to the efficiency gains.
Avoidance of subsequent adjustments
By taking usability into account during the development process, expensive reworking can be avoided. If a system is designed to be user-friendly from the outset, the customer does not have to spend large sums on optimizations later on.
Fewer errors
A user-friendly system reduces the risk of operating and input errors. Comprehensible feedback and logical processes help to avoid errors or correct them quickly. This also reduces the need for employee training and customer support.
Competitive advantage
All in all, products with good usability offer an all-round positive user experience. This strengthens a company’s market position, which is essential for the future viability of the business in times of high competitive pressure.
| Advantage | Impact |
| Higher customer satisfaction and loyalty | Users work without frustration and remain loyal to the brand. |
| Less time required | Tasks are completed faster and more efficiently. |
| Avoidance of subsequent adjustments | Early usability saves expensive rework. |
| Fewer errors | Comprehensible processes reduce operating errors. |
| Competitive advantage | Good usability strengthens image and market position. |
Which aspects promote usability?
- Clear and intuitive navigation:
users should always know where they are and how to reach their destination.
- A uniform design
The consistent design of colors, symbols and fonts facilitates orientation and reduces the learning effort. - Clear feedback
Ideally, the system informs users immediately about the success or failure of their actions. - Reducing complexity
Only the information and functions that are necessary for the respective activity should appear on the user interface. - Fast loading times
Good performance is essential to avoid high abandonment rates and long waiting times. - Mobile design
Websites and apps should also be usable without restrictions on the small displays of smartphones and tablets. - Personalization options
Whether individual language settings or customizable dashboards: The customizability of a system increases user-friendliness.
What methods can be used to measure usability?
Designers and UX experts have numerous test options at their disposal to assess the degree of usability. The most important methods include
Usability tests
Experts observe how real users perform typical tasks on an interactive system. In this way, difficulties in understanding and sources of error quickly come to light. Usability tests can take place either in the laboratory, remotely or under real conditions.
Heuristic evaluation
Here, experts evaluate a system on the basis of defined design principles, so-called heuristics. They identify typical usability problems without the active involvement of users. The method delivers results quickly and is particularly helpful in early development phases.
System Usability Scale (SUS)
The SUS is a standardized questionnaire that test persons fill out after using a system. It contains ten questions, each with five possible answers, and provides a numerical score between 0 and 100 points at the end. A score of at least 68 indicates good usability.
Eye tracking
During eye tracking, special measuring devices record the eye movements of users . This makes it possible to recognize where a person is looking during interaction. This reveals patterns that provide information about relevant elements such as buttons and navigation elements.
Click tracking and heat maps
This method records where and how often users click or move the mouse pointer. Heatmaps visualize the data and show which areas of an interface
Other methods are:
- A/B testing
- Card Sorting
- Design Thinking
- Tree Testing
- Interviews
FAQ about USABILITY
What is the difference between usability and software ergonomics?
What is the difference between usability and software ergonomics?
Does the user-friendliness of a website influence the search engine ranking
Does the user-friendliness of a website influence the search engine ranking
Which typical usability problems occur frequently?
Which typical usability problems occur frequently?
Can a system be designed too simply?
Can a system be designed too simply?
What role does the user environment play in usability?
What role does the user environment play in usability?
ERP system of the year – User Experience category
The ERP solution APplus from Asseco Solutions was named “ERP System of the Year” in 2025 – awarded for its outstanding user-friendliness and innovative operating concept.
The award underlines how consistently APplus makes the day-to-day work of companies simpler, more efficient and more modern.
