From the October 1997 issue of Entrepreneur

Let's say you've just come up with an idea for a ladies' shoe with interchangeable heels. How can you know whether this brainstorm would really work? And how would you explain your idea to someone else so they'd want to buy it? The answer to both questions: Make a prototype.

A prototype is simply a working model of your idea. Most of the time, it's not an exact model of the eventual finished product. In fact, it will most likely be very rough around the edges. However, it will provide you with a means to demonstrate your idea and give you--and investors--a glimpse at what your idea might eventually look like.

Many times an idea makes perfect sense in your mind. When it is turned into a working prototype, however, unexpected flaws appear. This is especially true for complex ideas needing many parts to work. The exercise of building a prototype will help you better develop your idea: You'll discover areas that need improvement and implement changes that could make your idea more valuable and marketable.

Having a prototype makes it easier to sell your idea to potential buyers, who can now see, touch, hear and smell your idea instead of visualizing what you're talking about from looking at drawings or reading a product description. It also proves your idea works, making it helpful in attracting investors, working with manufacturers and finding licensees.

What's Your Type?

Prototypes can serve a variety of purposes and can have a number of formats. Here are a few examples of prototypes you should consider:

vWorking model. This prototype (also called a breadboard) will demonstrate your idea's concept and how it works. It simply does what it's supposed to do without worrying about how it looks. This prototype is used in the early stages of product development to demonstrate functionality and communicate your idea to potential model makers or manufacturers so they can create a finished product for sale.

vPresentation prototype. The name says it all: A presentation prototype is created to present to potential investors or for promotional purposes. When you go to a car show and see an auto maker's "concept car," you're looking at a presentation prototype.

vPre-production prototype. A pre-production prototype looks and functions like the finished product. It is usually the last prototype made before the full-scale manufacturing begins. This prototype gives everyone a chance to inspect the product and make last-minute changes.

Build as many prototypes as you need until you are satisfied all the bugs have been worked out and that your idea is performing perfectly. This helps set a good idea apart from a great one.

Building Blocks

If your product idea is complex and way beyond your level of experience, you may have some difficulty creating a prototype--you may even need to hire someone to make it for you. But more often than not, you can make your own prototype if you're willing to roll up your sleeves and learn what is needed. Compiling the research to understand what goes into making and designing your product will help immensely when you start selling it.

Begin by writing down all the materials, supplies and tools you may need. Next, try to identify the various steps required to assemble your prototype. Creating a prototype is like building a model airplane: You don't make the body and then install the engine. Think about how each part works with the others and how each phase fits into the next. This exercise will be invaluable when you have your product manufactured.

Now identify those parts or materials you may already have around the house or can purchase easily. I've cut off the bottoms of prescription bottles and used the sides for tubing. I've removed spirals from notebooks because I needed a wire coil. If you're having trouble coming up with certain parts, think about what items can substitute for the missing parts. I had an idea for a pool gadget that required a waterproof motor. I found my answer when I went to a pool supply store: a battery-operated pool toy that had a motor inside.

If you can't find the part at home, the next step is to buy it. Some places worth exploring are hardware, grocery, fabric, craft, computer, building material, beauty supply, kitchen supply, and toy stores.

When building a prototype, don't try to reinvent the wheel. Keep in mind, right now you're just trying to get a working model of your idea, not the final production model. For now, make it easy on yourself and substitute.

In most cases, use standard parts. They're always easier to find than custom parts and will be easier to purchase in bulk when the product is manufactured. It's also easier to adapt parts for your prototype from existing products (such as radios, bicycles and so on) when you use standard items. Keep in mind, however, that if you can easily get standard parts, so can your competition. Using a few custom parts creates a barrier to entry for your competition.

Take your time when making a prototype; it will be more effective if you're patient and think through each step. Several good things can result from proceeding slowly and carefully. First, you may discover a change that could make your idea work better. Second, you may realize there are parts that you forgot to get or didn't even know you needed. And third, your frustration level will be reduced while you go through the process slowly because you will know that you thought each step out carefully and did not miss something by rushing.

Remember, the goal of a prototype is to prove your idea works. There will be lots of experimenting and tinkering. Don't become concerned over the material costs at this time. Right now, you are creating the most expensive version of your idea. Costs will get lower as you finalize your idea to its most efficient form and can reduce labor and buy materials in bulk at wholesales prices.

Going With The Pros

There will be cases when you simply must have someone else make your prototype. Typically this is when an expertise is required that would be too difficult or time-consuming for you to acquire. There are a number of professionals who make a living making prototypes, such as designers, engineers, product developers and so on. I've used these professionals in the past when I have needed to create a higher-quality prototype. I once worked on an idea that involved the use of electronics. After making a very crude prototype, I took it to an electrical engineer and told him how I would like my idea further developed. He was able to add features and functions that were simply beyond my capabilities. If your idea can be made better with someone else's expertise, I strongly recommend you use an outside expert.

A word of caution, however, before hiring a prototype maker: Make sure they can actually help you by communicating your needs to them and discussing the project thoroughly. Also, agree on a fee up front for the entire project. Prototype makers can charge high fees, and if you're paying by the hour, their fee can quickly escalate. Give them as much detail as possible about your idea; include drawings, if available. Remember, even a prototyping expert will not be able to produce a model of your idea if you don't tell them exactly what you're looking for.

Finally, the following story illustrates the importance of adequately protecting your prototype. A man made a prototype of a new fishing lure, then went fishing with it. Unfortunately, he learned how good his lure was when, after catching a string of fish, "the one that got away" took the prototype with it. You don't always need more than one prototype, but if you only have one, you should avoid situations where something like this could happen.

You may become very frustrated with trial and error when making your prototype, but try to keep it in perspective. The frustration and effort that goes into creating a model that actually works has never been more evident than with the many failed attempts in the early 1900s by inventors trying to develop a machine that could fly. Who knows how many failed attempts there were before the Wright brothers actually succeeded at Kitty Hawk in 1903.

Tomima Edmark is the inventor of the Topsy Tail, the Kissing Machine and several other products, and is author of The American Dream Fact Pack ($49.95), available by calling (800) 558-6779. Write to her with any questions you may have regarding inventions and patents in care of "Bright Ideas," Entrepreneur, 2392 Morse Ave., Irvine, CA 92614.