Designers cannot do everything their minds imagine. Design is limited or conditioned by four factors: the product or service itself, the context, the designer and the user.

1. The nature of the product or service itself

The essential components of a product, such as materials, weight or size, condition its design. These elements possess qualities that necessarily delimit the universe of possible configurations.

The case of services is more complicated because we are dealing with intangibles. Could we design a banking service as if it were a gym? From my point of view, the constraints are much more flexible, but although the boundaries are not evident, they exist.

2. The technological level and the paradigms of the time

In the mid-19th century, the English mathematician Charles Babbage created the Analytical Engine, capable of performing simple calculations. In the absence of electricity, the machine (of considerable size) operated through a system of gears.

In fact, that machine was the forerunner of the computer, but it was never finished because of the cost, the complexity of the project, and especially the low accuracy of the mechanical elements. Simply, the necessary technological base didn’t exist.

Babbage once said that his machine was ahead of its time. Very few people supported and understood the usefulness of a machine that was able to perform functions that people could do.

The mental models (paradigms) from which we interpret the world constrain the design as much as the physical elements. Could it have been designed a product or service centered in the user in the eighteenth century? No, because for the designers of that time this concept was non-existent.

the four boundaries of design

3. The knowledge, skills and preferences of the designer

This third constraint seems the most obvious one, since we have all encountered the situation of being limited by our own abilities. We all need to improve and our design is today definitely better than yesterday and worse than tomorrow.

The preferences of the designer, however, also affect the design. Sometimes it isn’t a matter of better or worse, but just different tastes and fashions. Yesterday people liked skeuomorphism, today flat design and tomorrow who knows.

4. The knowledge, skills and preferences of the user

In the age of user-centered design, this fourth constraint is clear. Analyzing the needs, abilities and preferences of users is essential to design a successful product or service.

This is not only about a product or service being appreciated. The knowledge and skills of users limit design possibilities. All the products and services require a minimum of knowledge and expertise to be understood and used properly.

If we design a digital marketing plan for a company, the first thing we should know is if there is any employee with a minimum level of knowledge about social networking and how much time they can devote to this activity. Depending on the answer we’ll have to design a plan or another.

If we are designing a website for a company, the first thing we should know is if any employee has the basic knowledge to manage it with a minimum of autonomy. Inevitably, a website for a company with workers trained in IT, social networking and content management must be different from a website for a company with two workers that are always out of the office, with minimal knowledge even of the Office tools, and only one computer.

Obviously, most design firms offer a few hours of training, but, from my experience, only those users with a sufficient basis are able to take advantage of it.