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The power of prototyping

Prototyping has always been an integral step in design and engineering, but practitioners are now expanding its use to various new applications and devising new methodologies to unleash the true power of prototyping. This is part one of the series on design thinking by the members of d.thinking Ponts ParisTech.

November 2010
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Prototyping has always been an integral step in design and engineering, but practitioners are now expanding its use to various new applications and devising new methodologies to unleash the true power of prototyping. This is part one of the series on design thinking by the members of d.thinking Ponts ParisTech.

The word prototype may conjure images of sleekly crafted model cars at an auto show or the new hot gadget being demoed at CES three months prior to launch. Companies, on the other hand, often see prototypes as resource-intensive milestones that are avoided when possible. These prototypes are often very refined preproduction or engineering models that are usually used to communicate the design to customers or to test the system (think crash testing cars). We often associate prototypes with nearly completed or just-before launch versions of products. However, designers create prototypes at all phases of the design process at various resolutions. What we see in the media is only the tip of the iceberg when it comes to the power of prototyping.

Communicating at every stage

Trade shows are filled with prototypes and demonstrations designed to get potential customers interested and excited. This is one way of communicating through prototypes, but different prototypes can be used at different stages of the design process. Early in the design process, very rough prototype can be better at communicating ideas to teammates and users than words or pictures.

Rough prototype from Ideo

(Source, Rough prototype from Ideo)

In a famous anecdote from Ideo, the design and innovation consultancy in Silicon Valley, a team of Ideo designers was working for Gyrus ACMI to develop new otolaryngology tools. In the early stages of the design process, the team was consulting a group of surgeons to identify issues with existing solutions and uncover their needs. During the meeting, a designer who wanted to articulate the idea that arose during the meeting scrambled together some odds and ends in the office and put together the above prototype. The surgeons immediately resonated with the prototype and started discussing further points of interest and improvement. After several cycles of development and refinement, Ideo ultimately delivered the Diego Powered Dissector System, pictured below. According to Perry Mykleby, senior director of marketing, Gyrus ACMI, ENT Division, Diego tripled revenues in the powered instrument product segment.

Diego Powered Dissector System

(Source, Diego Powered Dissector System)

When working with a consultancy or supplier, it is common to communicate designs, especially functional designs, through long specification documents. In some cases, these documents can be hundreds of pages with the fines of details. Some practitioners are starting to question the practice and relying more on prototypes to communicate their designs to clients and suppliers. Todd Zaki Warfel, the founder and principle designer of user experience design consultancy message first and the author of "Prototyping: A Practitioner's Guide" explained in an interview with Johnny Holland Magazine:

"In nearly every case in the past three years, prototypes have become our documentation. There are a few exceptions, where we need to include some supplemental documentation, say a 10-20 page document to specify some business rules that happen on the backend, which aren’t clear from the prototype. But I’m willing to do a 20 page spec document and a prototype instead of a 200 page spec."

Build to think

In engineering, students are taught to and practitioners think deeply before setting out to build. However, as the product or system becomes increasingly complex, it becomes increasingly difficult to consider all factors while designing. Facing this reality, designers are no longer just "thinking to build" but also "building to think." By getting hands on and trying to create prototypes, unforeseen issues are highlighted early, saving costs related with late stage design changes. This rapid iterative cycle of thinking and building is what allows designers to learn rapidly from doing.

Prototyping an automotive interface

(Prototyping an automotive interface)

Creating interfaces often benefit from the "build to think" approach. For example, in trying to layout the automotive cockpit, one can simply list all the features, buttons, and knobs that must be incorporated. However, by prototyping the cabin does one really start to think about how the layout should be to the driver in order to avoid confusion while maximizing comfort. This then allows the designer iterate on their initial concept to develop something that is more intuitive and refined.

Rough, Rapid, and Right (Test early, fail often, succeed faster)

There is a tendency for designers to create the perfect prototype before sharing with others and testing on users. However, in the design community at Stanford University, prototyping is often done under the mantra "rough, rapid, and right." The belief is that the purpose of prototyping is beyond communication and is to test underlying assumptions and answer questions regarding the design. Therefore, prototyping should be done quickly and just good enough to answer the questions at hand. For example, to test how users interacts with new interface concepts for a phone, sketching screenshots and buttons can answer just as many questions as a highly refined software prototype on mock hardware.

In ME310, a full year project-based design innovation course at Stanford University, a team of students working with BMW was given the challenge of "improving the open air experience" in a 3-series convertible. As most convertible drivers know, driving top-down at high speeds on the highway creates a bizarre recirculation effect where inconsistent wind blows from the back seat to the front. Hairs of the front passengers are blown into their faces, and the noise is distractingly annoying. The current solution is a clunky mesh screen that is installed in the back seats effectively turning the four-seat convertible into a two-seater.

Rough prototype for convertible comfort

(Rough prototype for convertible comfort)

The student team, hypothesizing that the noise is the main source of annoyance, created the five-minute prototype pictured above to test the effects of shielding just the ears of the driver. Testing the sunglass and plastic cup prototype confirmed that ridding the noise made for a much better open air experience. As BMW drivers couldn't be expected to look like clowns on the road, the student team then tested the newest technology in noise cancellation embodied in the Bose QuietComfort 2, the most advanced headphones available to consumers at the time. Testing the headphones revealed that while they worked perfectly in airplanes, they were incapable of canceling out wind noise in a convertible. Further consultation with a professor specializing in signal processing uncovered that no technology was currently available to remove inconsistent noise in convertibles. Through two rapid iterations of prototyping and testing that took less than a day, the student team was able to test a correct assumption, an inadequate solution, and move onto the next concept.

Prototype of a fak” gesture based control system

(Prototype of a “fake” gesture based control system)

For another project in ME310, a team working for Volkswagen was given the challenge of creating a new interface for the non-driving functions of a car, i.e. climate control, audio control, etc. Noting the recent advancements in computer vision, the team identified early on that gesture control could be a viable alternative to the increasingly complicated button-and-knob paradigm of today. However, before developing and adapting the technology for automotive use, the team wanted to verify that such a system would be intuitive to the user. Over the weekend, the team created a driving simulator and a "fake" interface where the video feed capturing the gestures were sent to a human operator behind the scenes controlling the different features of the driving simulator. Through testing this prototype, the team was not only able verify the intuitiveness of gesture control but also discover various gestures that were natural to people. The team then spent the next eight months implementing a real gesture recognition system in a prototype car.

Various prototypes for various purposes, industries

When suggested rough, rapid prototyping, people often respond with "you can't prototype what we do," or "we have to build the whole thing before we can test it." This is often due to the lack of imagination and the inability to see beyond the existing paradigm. With a little creativity, practitioners in the field of design and beyond are harnessing the power of prototyping to develop their products, services, processes and more.


The user interface and web design community is increasingly prototyping with paper before writing a single line of code. The time required to program software interactions and create screen shots is much more than the time it takes to draw several screen shots and switch between them by hand. The extra time gained by using paper prototypes can then be used to test more concepts and better refine them before writing the software. Above is an example video of a designer testing a website interaction by walking through the screen shots with the user.

In the video game industry, EA Games, the largest video game publisher in the US, is known to prototype their games by creating card games to simulate the interaction. Only after the card games are refined to the point where the experience is "sticky" are the first software prototypes made. Again, the resources saved by using a lower resolution prototyping medium allow EA to experiment with more concepts and ideas.

In the service industry, experience prototypes are regularly created where users are put through a role-play to experience the simulation of a service. Over the last decade, Ideo, has been working with more and more service providers in addition to product companies in order to redesign and create new customer experiences. Example clients include the American Red Cross, Mayo Clinic, and the Bank of America. Working with these companies, experience prototyping was critical in creating and testing new service concepts.

Tangible Business Process Modeling in action

(Photo courtesy of Jonathan Edelman, Tangible Business Process Modeling in action)

Even in the field of business and management, prototyping is being used to more effectively design business processes. Traditionally business process modeling have been done through workshops facilitated by process analysts and software modeling tools. Researchers Jonathan Edelman and Larry Leifer at Stanford University's Center for Design Research and Hasso Plattner Institute in Germany are experimenting with what they call Tangible Business Process Modeling (TBPM). TBPM utilizes dry-erasable acrylic blocks of different shapes and size as building blocks for the modeling process. Researchers are discovering that the very tangible and low-resolution prototyping tool invites more stakeholders in the workshops to participate in the model creation and iteration process. By using physical objects that everyone knows how to handle, more people are getting involved in the modeling process, allowing for faster iteration and higher quality outcomes. There are talks that the TBPM toolkits will be commercialized soon for businesses to implement.

In Conclusion

Only in mankind's recently history has there been such a clear distinction between prototypes and final products. Before the age of mass manufacturing, every product was a prototype for the next product as craftsmen learned and improved from every version he or she created. With the coming of the age of science and analytical reasoning, man's ability to engineer and produce has reached levels never seen before. At the same time, we gained hubris, thinking that we could analyze our way into what we want, desire, and need. In a world where systems, technologies, and societies are becoming increasingly complicated, what we need now is to return to our roots where we prototyped and analyzed to the solutions. Let's harness the power of prototyping.

Sushi Suzuki
Instructor of design innovation at école des Ponts ParisTech and co-founder of d.thinking Ponts ParisTech