Prototyping Part 3 – Functional Prototypes

This post is the third and final in a series of three dealing with prototyping. In the first instalment, I discussed why we prototype – the reasons are many, but essentially boil down to ensuring that our designs anticipate all requirements and meet them as well as possible. The second dealt with visual prototyping, vitally important in ensuring that our designs look great in and of themselves, and in their environment. In this post I’ll deal with functional prototyping – a critical step in assuring utility and usability in many types of design. In my experience, there are three main types of functional prototype:

– Proof of Concept – This type of prototyping is part ideation and invention. It’s a way of moving from sketchbook to three dimensions as quickly as possible. Most things that are manipulative or interactive in nature can be simulated in simpler ways to determine if they have enough merit to develop further. The methods of producing these proof of concept prototypes usually involve things like cardboard and hot glue – nothing sophisticated. Sometimes, things can get a bit more serious, using wood where later it would be aluminum, but the prime objective is to quickly and inexpensively develop a design that works. If you want to know more about this class of prototyping, check out Paul Orselli’s blog¬†ExhibiTricks, he’s written extensively on the subject.

– Dimensional – Mostly this is a way of confirming scale and functionality. It can often be extremely inexpensive to carry out, as it can involve mock-ups with objects from around the office. For me, it often serves as a way of confirming what existing ergonomic data might suggest, especially when data for a very specific application is not available. This might be the height or depth of counter surfaces, or the mounting height for an interactive. With a bit of quick testing with a tape measure and some post-it notes, we can avoid costly mistakes. In environmental graphic design, it can offer us ways to confirm typography in specific settings, by using full-scale prints for physical readability testing. For both exhibits and signage, site conditions can render “standards” less than optimal. Physical on-site prototypes are often the best way to have confidence that layouts are optimally readable.

– Pre-production prototypes – As the name suggests, this is a sort of last call for refinements before we commit to production. This type of prototype should be done in the real materials and finishes. The best scenario for this category is to establish a fabrication contract and have that fabricator produce an initial instance of the design(s) to ensure that everything works as expected and that there are no surprises in assembly, fit or finishes. As with other kinds of prototyping, it’s OK to isolate only certain details for prototyping, especially when the budget is tight. To treat fabricators fairly, contracts should anticipate this step so that fabricators are all bidding on the same thing, and are fairly compensated.

If you’re a designer, I encourage you to use prototyping in all its forms to produce better designs. If you’re a design client, I hope that this series of posts has helped you to see that prototyping doesn’t cost, it pays!

Have any success stories with prototyping you’d like to share? Words of wisdom? Did I leave something out? I look forward to hearing from you