It seems like a lot of work and cost to build a prototype - and perhaps a big unnecessary, expensive step. Why not just do the design really well, then send it to production? Why make prototypes? What is the purpose of a prototype anyway?
Let's try to answer these questions by looking first from 10,000 feet. (Big Picture.) Obviously, there are differences with each product and for each person and situation. However, there are some guiding principles in the purposes and therefore why we make prototypes.
We believe every prototype should have a unique purpose. That purpose must justify both the cost and the learning, because the real purpose of a prototype is to increase understanding. And, the prototype methods should do it effectively.
Product Development - A High Level View
The term "Product Development" is how we describe the process of bringing a new idea from concept through to a product ready for a customer to buy. It is the whole process of iteration through many steps. The number of steps and iterations depends on the project. Here is a simplistic graphical representation. Let me emphasize the word "simplistic" because there is a lot involved that is not in the diagram.
/p>
It starts with an idea. Refining is thinking about how the new thing will work, look, etc., then adjusting to make it better. Often this is done subconsciously as you reflect about this new "Thing", while other times the process is more explicit like brainstorming, or a design sprint, or another thinking process.
Let's not bog down in the details, because we have written extensively about The Product Development Process and even more in the Inventors Lab. If you are thinking to make prototypes or about bringing a product to market, we definitely recommend reading these articles too.
In general, as the idea solidifies, the next step is design and maybe engineering. Again, there is a lot, but in the process of design, there are often questions that need some proof. Perhaps around function or feel or manufacturing. Even if the only real question is "Does it all work the way we think?" Answering those questions is where we make prototypes - maybe as a complete product, or maybe just the portions we need to test.
The diagram shows going round and round with refining, design, prototyping. It is honing the idea, learning and perfecting until it is ready for production. Every prototype should answer questions, then ask new questions too - bringing refinement and better design as we approach production.
What Is A Prototype?
We all have our ideas of what a prototype is, and usually our perspective follows the industry we are in. Honestly, the definition is vague simply because there are so many different reasons to make prototypes. For some people prototyping is just the first build of the new product, while to others, it is a piece of the product - the piece that needs testing.
To some people a prototype is only a representation - to show or to analyze. To still others, a prototype is a loosely related thing to convey ideas - like bailing wire and duct tape.
While very different, all of these definitions are correct.
I dislike the more modern term "Hack", but that is what some people call the prototyping experience. I suppose it is often a first interaction with a product, so "hack" has some validity. Though it is a little misleading, if it helps you . . . that's great.
At Synthesis, we like to make prototypes as a tool - a representation made to answer a specific purpose. Usually that means a physical item or contraption (like these), but sometimes it is virtual - like a CAD model or code. As a representation, a prototype may be crude and rough, or more refined - hopefully driven by the desire to effectively demonstrate or answer the reasons it is made.
What Kind Of Prototype?
To be effective, the prototype should uniquely answer the needed questions about look, feel, or function in an easy way. Sometimes we think about the kinds of prototypes with respect to the material, which can be true, but I like a broader perspective. Just because we make something with 3D printing, does not mean it is a prototype.
For our goal of understanding why we make prototypes, we must first understand that there are many good reasons - not just one. Above we said the prototype should uniquely answer questions, yet that just brings more questions: What kind of prototype do we need? A "Looks Like" prototype? Maybe a "Functions Like" prototype? A "POP" prototype? Or, a "Complete" prototype. (Or, perhaps some variation or combination.)
With each of these descriptors, "Looks Like", "Functions Like" "PoP", there is also a scope. We can examine those more closely.
Examples of Why We Make Prototypes
Understanding the purpose, also points out the "Why". Since examples make great illustrations, we will use stories to explain. That is more fun than rehashing the theory anyway.
Looks Like:
When we make prototypes that "Look Like" the final product, they may be paper mache or clay or something else. They may only include one area the end customer will interact with. (Maybe to see how it feels, or how it fits with something else.)
See the photo of the foam grip made to see how it fits and feels in a hand. It is very hard to design "feel", so we make prototypes as a great tool for that. In this case, it is only a portion of the actual product, and it's totally non-functional, but it "Looks Like" the real thing - almost. Adding weight inside also makes it "Feel Like" the eventual product. (Well, except the texture, but that is not needed.)
Another example. Working with one company, we sent out a typical package of drawings for quote. To some vendors, we gave only the drawings. To others, we included an SLA of the part along with the drawing package for quote. Because it was a rather complex die casting, the prototype gave the second set of vendors something to look at, to hold, and to visualize. The second set of quotes were all about 20% lower than the first. The purpose of those prototypes was visualization, and they more than paid for themselves in cost savings. We also believe they improved part quality because the tool makers understood better what they were making.
Functions Like:
Or "Acts Like". As you might guess, when we make prototypes for function, we don't worry so much about what it looks like. These are the "Functions Like" prototypes that we use to actually "try out" or test an idea - to see if it works.
The image here shows a test piece for a product. The first round did not work as desired, so this is the second version where we cut some inserts and put them in to make it work better.
The description "Duct Tape and Bailing Wire" can often describe how we make prototypes like this. Often they are not so pretty, and usually they are cobbled together with things hanging about - wood, wire, tape, clay - you get the picture.
For inventive items, this is where the rubber meets the road to see if the idea even works. More importantly, these are the physical items - especially in bailing wire and duct tape modes - which allow optimization in ways that are more efficient. They are prototypes, even if they are ugly. They are tools for learning, even if outsiders can't see them that way.
Here is another article showing a prototype to test the function. In this case, we needed to know how a vicious dog would react. What better way to find out than to make a functional prototype?
PoP - Proof of Principle:
Very much like the above description of "Functions Like", PoP's are to prove a concept. With a new product, it is important to identify areas where there is a technological stretch. If possible, testing these bits first (even if in a cobble), to learn, before committing to a full prototype is very helpful. Hence, the name "Proof of Principle".
The image here shows a fab portion (clamped and ready to weld) to test fits and angles for a support to eventually become this patent.
Another example. When designing a special new device for a customer, we wondered if one of the concepts for cutting could even be done. How can we hold these tiny flexible pieces while slitting them in a particular way? Several ideas were prime, but would they really work?
We took a day to make prototypes and cobble some things in the shop with wood, PVC pipe, wire mesh, screws and tape. We also had to weld a couple brackets to hold it together, yet in about a day, our first "PoP prototype" was done and tested. It looked cobbled, or worse. My son said "I think this is the most crazy way to make prototypes we have ever done!"
But, it simulated the concept and taught us a bunch of important things. As we learned, we modified until the process worked. We did have some hiccups in learning, but that is exactly what a PoP prototype is all about. Now we have a concept with confidence to design it into the final product.
Complete, or Full Prototypes:
Obviously, the full proto is the whole product. If your product is simple, like the yellow one in the photo, then a full prototype is practical, even early. If your product is more complex, consider one of the "partial" prototyping versions above.
The Yellow product is a good example of the value that comes as we make prototypes. The image shows the final product, but there were actually 3 versions of prototypes. A first version was crude and simplistic, but it showed the possibilities. A second version included a lot of changes, and begged the questions that brought us to the final shape - and the sticky over-mold lining. No matter what you think of the idea at first, prototypes will help you refine, optimize and improve the idea in ways that only a physical item can.
To illustrate full prototyping further with extremes: If your product is a car, you might want to prototype the engine separate from the suspension, separate from prototyping the body. The complete product prototype will be a later stage of development.
Another simple product, this one for gun scopes, we made with full prototypes.
The Purpose of Prototypes
In the throws of development when both time and money are tight, prototypes can seem so expensive. They take extra time to design and build, so we often ask: "why do we make them?" and "What is the purpose to make prototypes?" Hopefully with all the above, these questions and their answers now make more sense.
Let's pause the discussion here. This is a topic I could talk about all day, yet we have addressed so many of the details already. Some here, and some in the article links on this page.
To us, prototypes are "the Design Verification phase of Product Development" - because it demonstrates or proves the design." A quote from Step 5 in the Product Development Process article. From a high level view, that is the purpose, and that chapter expands on the Why's, When's and How's. For more information, please follow the links to read more.
A Product From Prototype
Here is a final example of where the prototype is the product. The "idea" is a new configuration for a light-duty trailer suspension. We built it, we tested it, we changed it, tested again, then completed it and use it frequently. The original intent was to just "see if it works", but with the success, we decided to share.
The prototype became the physical representation and proof through design and refinement. Engineered plans with this design are really the product. Though it was not the original intent, plans are now available here. The funky suspension system in this trailer is the prototype, which gave time to optimize. Read about it here. And, if you are interested, you can read about the engineering in Part 1, then also in Part 2.
We make prototypes to verify something - to answer questions - to demonstrate - to convey ideas - or to test. Whatever the concern, make prototypes to learn. If the prototype is big or expensive, get the most out of it by learning as much as you can. (Or make a scale version if you can learn what you need.)
Ask the "Why" questions about every aspect of it. That is the way to make prototypes pay you back for the effort.
Summary - Why Make Prototypes?
The purpose in building a prototype varies, and with variations are the differences in "Why". We have built them to test ideas, to destroy in finding limits, or to express the idea in a way others can understand. We have made them for Trade Shows, and for meetings with investors. We have even made them for focus groups to see how people will react. It all depends.
There are so many reasons to make a prototype, and just as many ways to build them. Hopefully this article has expanded your view of the word "Prototype". It is, to us, a very generic word - like "car". There are Sports Cars, Family Cars, Sedans, Coupes, Trucks that people call Cars, Old cars, New Cars, Beater Cars, Electric Cars, . . . You get the idea.
A prototype is just a tool for moving you toward a larger goal. In the end, it is a great way to increase understanding.