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Form and Function in Design

Form and Function in Design

By Tojin T. Eapen

Form and function are two fundamental characteristics of design that work together to create a successful and aesthetically pleasing product or system. Form refers to the visual appearance or outward design of an object, while function refers to its intended purpose or behavior. 

In design, form and function must be carefully balanced to create a product that not only looks good, but also performs its intended function effectively. A product with a visually pleasing form but poor function will ultimately be unsuccessful, while a product with excellent function but an unappealing form may not be as well received.

In this article, we discuss three principles that relate to the relationship between form and function in design. The first principle is "form follows function," or in its original form, "form ever follows function." This principle suggests that the form of a product should be designed to support and enhance its function. The second principle, "function follows form," suggests that in some cases it may be advantageous to design the form of a product first and then design the functions to fit within its constraints. The third principle, "separation of form and function," recognizes the importance of designing form and function independently and in isolation, and then combining them in a loosely coupled fashion at a later stage in the design process.

Form Follows Function

"Form follows function" (FFF1) is a principle in design that suggests that the form or appearance of a product should be determined by its intended function or purpose. This principle is often used to guide the design process, ensuring that the product is not only visually appealing, but also highly functional and effective. The principle originates in the design dictum "form ever follows function" which was coined in 1896 by American architect Louis Sullivan (1856-1924) in his essay, The tall office building artistically considered. According to Sullivan:

Whether it be the sweeping eagle in his flight, or the open apple-blossom, the toiling workhorse, the blithe swan, the branching oak, the winding stream at its base, the drifting clouds, over all the coursing sun, form ever follows function, and this is the law. Where function does not change form does not change. The granite rocks, the ever-brooding hills, remain for ages; the lightning lives, comes into shape, and dies in a twinkling.

Sullivan argued that a building's form should be determined by its function, and that any ornamentation or decorative elements should be derived from the building's structure and purpose. This principle became a guiding principle for the modernist movement in architecture and design, and it has since been widely adopted in various fields of design.

Function Follows Form

A paradigm that inverts the traditional thinking of "form follows function" is "function follows form" (FFF2), or "Form Leads Function" (FLF) where the goal is to design a product with a novel or superior appearance and then design the functions within the limitations imposed by the form. There are at least two situations where this dictum may be sensible to apply.

The first situation is when the primary goal of the design is the aesthetic itself. For example, for many products, the determining factor for their value is their appearance. Handbags, jewelry, watches, and even expensive cars are sometimes able to command a premium price due to their visual appearance that distinguishes them from less expensive items. In these cases, an implicit assumption is that the constraints imposed by the form are not sufficiently limiting, and the core function can be provided independently of the form itself.

Another reason that the FFF2 paradigm may actually be a more pragmatic approach is that it can be challenging to design the form around optimized functions. This can result in products that are designed primarily with function in mind appearing drab and unattractive. By starting with the form and designing the functions to fit within its limitations, it is possible to create a product that is both aesthetically pleasing and functional.

The "function follows form" principle may also be a powerful tool to avoid biases that can arise during creative thinking, such as functional fixedness and design fixation. By starting with a novel design and then designing the function to fit within its constraints, the designer is challenged to think creatively about how to incorporate the function into the form. This approach can help to break free from preconceived notions about how a product should function and allow the designer to consider a wider range of creative solutions.

Moderate levels of constraints have been shown to be associated with higher levels of creative production. Therefore, the constraints imposed by the form on the function may actually result in superior functional designs compared to designing for function without any constraints. By using the "function follows form" principle, designers may be able to generate more innovative and effective solutions to design challenges.

The "function follows form" principle also finds application in design when generative artificial intelligence (AI) technology is used in the first stage to create raw concepts. In these cases, the AI is better suited to identifying novel forms when no constraints are imposed. These novel forms can then be used as a starting point for designing novel functional features that may not have been recognized without the form imposing the demand for such thinking.

For example, a designer may use generative AI to create a collection of novel form concepts for a new type of chair. The AI may generate a range of concepts that vary widely in their appearance, from simple and minimalist to complex and sculptural. The designer can then choose a form concept that inspires them and use it as a starting point for designing the chair's functional features, such as the type of materials to use, the size and shape of the seat and backrest, and the type of leg or base structure to support the chair.

The "function follows form" principle is particularly useful in these cases because it allows designers to break free from preconceived notions about how a product should look and function. By starting with a novel form, designers are forced to think creatively about how to incorporate the necessary functions into the design, given the constraints imposed by the form. This approach can lead to more innovative and effective designs that may not have been possible with traditional design approaches.

Separation of Form and Function

The "separation of form and function" (SFF) principle is a design approach that suggests that form and function should be dealt with independently and in isolation, and then joined together in a loosely coupled fashion. This approach allows designers to focus on each aspect of a product independently and optimize it before combining them. The form of a product can be designed separately from its function, and the two can be brought together at a later stage in the design process, once they are both completed.

One example of the application of the SFF principle is in the design of physical products. In this case, the functions of the product might be contained within a "box," while the form of the product is designed separately and then applied to the box. For example, a designer might design the form of a phone as a sleek and slim case, while the functions of the phone (such as the display, processor, and battery) are contained within the box. By separating the form and function in this way, the designer is able to optimize each aspect independently and create a product that is both aesthetically pleasing and highly functional.

In software design, SFF is encapsulated in the "Separation of Concerns" (SoC) principle. This principle was coined was coined by Edsger W. Dijkstra in his 1974 article, On the role of scientific thought. One well-known example this is the use of HTML/CSS in website design. HTML is used to define the structure and content of a web page, such as the headings, paragraphs, lists, and links. It is responsible for the underlying function of the web page, but it does not dictate its appearance. CSS, on the other hand, is used to define the visual appearance and layout of the web page, such as the font, color, size, and positioning of the elements. It is responsible for the form of the web page, but it does not dictate its underlying function.


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