Product Design Principles Essential for Success

Whether it’s an app interface, a perfume bottle or a toaster, product design principles ensure it satisfies customers’ expectations regarding ease of use, functionality and aesthetics. Meeting — and ideally, exceeding — those expectations is foundational to the success of the product and the brand. Those expectations are foundational to the success of the product and the brand.

Persuasive marketing might convince consumers to try a digital or physical product. But if product design principles aren’t adhered to, the item is apt to not perform as it should, be too complicated to use or be deemed ugly. Not only will people stop using it, but they might also sour on the brand altogether. What’s more, they’ll make their dissatisfaction known — and as every brand knows, negative reviews and word-of-mouth linger and are hard to overcome.

Product design might be an easy thing to overlook as you’re starting a new business or launching a new product, but brands should ignore product design at their own peril.

6 Core Product Design Principles

Product design and industrial design are sometimes used interchangeably. Most practitioners agree, however, that product design is a subcategory of industrial design. While there is overlap, industrial design principles focus as much on the benefits to the brand as to the end user, taking into consideration practicalities such as manufacturability, regulatory compliance and sustainability. Product design principles, including the six below, are above all else user-centric.

1.     Functionality

“It does what it says on the tin”: This tagline for a wood sealant is so fundamental to what consumers want, it has become a popular idiom in the UK. Consumers first and foremost need their products to perform as they are supposed to, which is why functionality is among the primary product design principles. That said, the function needs to be one that solves a problem or satisfies a desire. Someone could design a chewing gum that tastes like Brussel sprouts, but no matter how authentic or long-lasting the flavor, it’s safe to say there’s no need or desire for such an item, and therefore it wouldn’t be considered functional.

2.     Usability

You buy a new game controller that’s compatible with multiple platforms and promises low latency. It performs fine, but the buttons are placed in such an awkward arrangement, and the grip is so slick that it’s difficult and uncomfortable to use. This example demonstrates how usability differs from functionality but is just as important. Well-designed products make it easy and intuitive for consumers to enjoy their functionality.

3.     Aesthetics

In terms of product design principles, beauty differs from aesthetics. There are some universal tenets of aesthetics involving balance, contrast and proportion; there may also be brand-specific rules such as the use of certain color palettes. Perhaps most important regarding product design, however, is that appearance does not undermine usability and functionality. No matter how pretty the CTA buttons on an app are, if they are too small to be easily pressed or too subtle to be noticeable, they are an aesthetic miss.

4.     Consistency

When consumers know a website’s navigation bar will be on the top of each page, or that the on/off switch for your brand’s countertop appliances will always be on the bottom, they find the product much easier to use than if they have to hunt around for what they’re looking for. This consistency creates a sense of familiarity with both the product and the brand, which subsequently leads consumers to view product and brand alike as reliable and trustworthy.

5.     Accessibility

For some types of design, such as websites and buildings, accessibility is a legal requirement. But even when it’s not, ensuring digital and physical products can be used by people with a wide range of capabilities is best practice and common sense. Many accessibility features, such as easy-open packaging and high-contrast visual displays, complement other product design principles, including usability and functionality. The electric toothbrush, for instance, was originally designed for people with limited motor skills, while closed captioning used to be exclusively for those with hearing impairments; both products are now popular with consumers at large.

6.     Affordances and signifiers

Like accessibility, affordances and signifiers contribute to other product design principles. Affordances are properties that suggest how something can be used or the benefits it provides. Signifiers indicate to the user how to achieve that use. The door is a classic example. Upon seeing one, a person understands that it affords the ability to exit a room. A lever on the door signifies that the person needs to turn it in order to take advantage of that ability. In a well-designed product, the affordances of the functionality are typically intuitive or obvious, while the signifiers ensure easy usability.

Product Design Principles in Action

Commercial drinking straws had been around for several decades when, in the 1930s, Joseph Friedman noticed his young daughter was finding it difficult to drink her milkshake from its tall glass using a traditional straight straw. A straw that could bend over the lip of the glass would solve the problem, and Friedman got to work designing one. The corrugations he added solved the problem and added functionality. And because the straws were disposable, hospitals found them more usable than the glass drinking tubes they’d been using to enable prone patients to drink. In fact, this accessibility resulted in healthcare facilities being the first customers of the Flex-Straw, aka the “bendy straw.”

That flexible straws are still produced and used today is a testament to how they solved a problem and satisfied a need by adhering to core product design principles.

A more modern product that demonstrates the importance of product design is the Duolingo language education app. By offering free and premium versions, Duolingo makes the app accessible to a wide range of consumers, while the compact length of each lesson makes the app usable for people who don’t have time to attend traditional classes. The colorful cartoon visuals add aesthetic appeal while suggesting learning can be fun rather than a chore, which is underscored by the built-in gamification. The clean, consistent user interface, with its intuitive signifiers, adds to the ease of use.

How to Apply Product Design Principles

Since functionality and usability are critical to a product’s success, the first step to applying product design principles is user research. This enables you to understand exactly what your target audience needs and wants, as well as their current pain points.

Assuming that users have the same needs you do is an easy mistake to make, which is why conducting qualitative and quantitative research from the beginning is key.

Once the design process is under way, wireframes and prototypes enable usability testing early on. Issues can be rectified much more easily and affordably when they’re caught sooner rather than later. The feedback you receive from these tests allows for user-centric iterations that optimize not just functionality and usability, but also aesthetics and other product design principles.

Testing and iterating shouldn’t stop once the product has been brought to market. Continued user research enables continuing improvement to ensure the product keeps up with changes in consumer preferences and the competitive landscape.

How Material Can Help

Incorporating product design principles requires much more than design expertise, vital though that is. Market research, consumer insights and usability testing will ensure design principles are implemented in a way that satisfies consumers and generates revenue, profits and brand loyalty.

At Material and our in-house design studio, Aruliden, we have expertise and experience in all aspects of product and industrial design, from research and prototyping to liaising with manufacturers and honing digital interfaces. Contact us today to learn more about how we can help with your physical or digital design needs.

FAQs

How do product design principles affect user experience?

User-centricity and the user experience are intrinsic to a well-designed product; in fact, usability is one of the key product design principles. Consistency, accessibility and affordances and signifiers are other core product design principles that address user needs and lead to an intuitive, simple user experience.

Are design principles the same for digital and physical products?

The fundamental product design principles of functionality, usability, aesthetics, consistency, accessibility and affordances and signifiers apply to digital and physical products alike. How they are implemented might differ, however. For instance, usability in a digital product such as an app would focus on navigation and interfaces; in a physical product, ergonomics, size and weight would likely be important elements.

What’s the difference between UI and product design?

User interface (UI) design is a subset of product design concerned exclusively with how users interact with a product. User interfaces range from speech recognition to app menus to the control knobs on a stove. Product design encompasses how users engage with the product as well as myriad other elements, from how well the product meets users’ needs to its sensory appeal.