It is a design process that focuses on designing things for human use, so that people can use them to get their jobs done simply, efficiently, comfortably, safely and enjoyably.
The fact that people use them does not mean they are designed for human use. If they were, we would have fewer problems or difficulties using them. Yet we have all experienced using things that confuse and frustrate us. People continue to press the wrong lift buttons, have difficulty using many features of their mobile devices and cameras, are frustrated trying to record TV programs on their digital recorder, scald themselves because they turned the shower mixer the wrong way or end up making wrong turns because they failed to read road signs and signals properly. Many accidents attributed to 'human error' usually involve poorly designed equipment and user interfaces.
That's true but designers often make the mistake of referencing themselves, with the assumption that if they can use whatever they are designing, then other people can too. That's only true if we all think and behave alike. In reality, people are different in terms of their physical dimensions, capabilities, knowledge and experience. We often rely on our knowledge and previous experience to figure out things, to understand and use them. Some things that appear obvious to some of us can be totally non-obvious to others. "It's so simple my grandmother can use it" isn't a guarantee of ease of use - that designer's grandmother might be a rocket scientist!
As humans, we have been created to sense, think, act and behave in certain ways that are uniquely human. We share certain natural capabilities and limitations though there are variations among us, for example in physical stature and in the way we perceive things due to our cultural and environmental contexts. There are certain design principles that govern how we should go about designing things in ways that best fit these human characteristics, capabilities and limitations - things designed in this manner feel natural and intuitive to use.
When things violate these design principles, users can still use them since by nature humans are adaptable. But these things are more difficult to learn, understand and use, are less comfortable, cause more mistakes and may be unsafe. On the other hand, things designed for human use accommodate these human characteristics, capabilities and limitations, resulting in designs that are safe, comfortable, simple, natural and intuitive to learn, understand and use. It also allows people to use them efficiently to perform their tasks.
User-centred design principles apply to all things that people interact with: products, systems or environments. They don't apply if your design requires absolutely no user interaction (like a featureless box you keep hidden in a room) or if they are not intended for people to use. If you're designing a bird-house, dog kennel or hamster toy, you'd be better off understanding birds, dogs and hamsters to do a good design. You'll also end up with happier and more satisfied pets!
We often think about 'interaction' as something we do with controls and displays on products. But we can also interact with a system or environment. When you buy a burger from a fast-food outlet, you are interacting with the system they have put in place to serve customers, from how customers should queue to the ordering and payment process. When you use the public mass-transit system, you are interacting with the system they have put in place from purchasing tickets from machines, information displays, route maps, entry and exit barriers and the trains and vehicles you ride in.
Failure to design for human use in any product, system or environment often leads to mistakes, confusion, frustration, wasted time and poor customer experience.
The process focuses primarily on understanding who the users are, what tasks they want to accomplish, how they go about accomplishing those tasks and the context within which they perform these tasks. Such information includes an understanding of user characteristics, capabilities and limitations, experience and knowledge level, the current and alternative methods used to perform their tasks, the actions and steps they have to take, and the physical, social and environmental setting in which the tasks are carried out. This information is used to derive design specifications and drive the design from start to end. The process ensures that designs are regularly reviewed and tested with users to ensure that it satisfies these requirements.
The more we understand users, tasks and the context of use, the more we are able to do a good job in designing things that enable users to accomplish their tasks simply, efficiently, comfortably, safely and enjoyably.
1. Improves customer experience
User-centred design allows customers to feel safe, comfortable, confident and productive when interacting with the design. They feel good about it and enjoy their experience with it. As a result, companies and organizations gain satisfied customers who are more likely to continue using their products, systems and services and to spread the word to other users.
2. Improves competitiveness
When customers have a good experience with a product, especially at point-of-sale, they are more likely to purchase it. More customers are looking for products that look good, are simple & efficient to operate and are comfortable to use. These are values that help differentiate your product, system or service from your competitors.
3. Improves design quality
Important user and task needs are identified early in the design and become part of the design goals and specifications. When we begin with good design specifications, we end up with better and more competitive products, systems and solutions.
4. Saves time & money
Bad design with serious safety consequences can result in costly product recalls. Late identification of usability problems that require design modification halfway through the development cycle can be costly and delays project schedules. Difficult to use products, systems and solutions result in a lot of technical support calls from customers, increasing support costs. User-centred design solves these by identifying and avoiding many of these potential problems early in the development.