Why Use Prototypes
Why do you use prototypes?
- To better understand the customer?
- To determine whether the technology works?
- To see whether your product concept is manufacturable?
All of these are valid reasons to use prototypes during product development. However, sometimes companies wait until late in development to collect feedback. They often think the prototype has to be functioning in order to obtain useful feedback and information.
Prototypes have many different roles in product development. Because of these different roles, the form and expectations of a prototype should change as you proceed through the product development process. Below are some common ways prototypes are used and the forms it may take.
Customer
During the earliest parts of product development, prototypes are used to explore customer needs and market acceptance. Often artist renderings or handmade rough approximations are sufficient. (These are sometimes called pretotypes.) Don’t overthink the prototype early in development. Use something that approximates the concept, or a portion of the idea, in order to collect the relevant information.
For example, if you want to understand the acceptable size and weight of a surgical hand piece for use by female surgeons, a milled piece of plastic or a 3-D printed model may be good enough to obtain information. If you are developing software, a mock-up of the user interface (UI), instead of real working software, is often enough to collect information on how the customer might interact with the UI or whether they even find value in the concept.
As the product is designed, structured reviews of the product with customers should be held. The objective includes ensuring the product design continues to meet the customer’s needs, but you may also collect feedback about design tradeoffs or information on how a person interacts with the product (human factors engineering or HFE). This information provides additional input which is used to further refine your design.
Technical
Technology can often take years to develop and you may need to try many times before you have something that works. Prototypes are the way to build knowledge about a technology. Early in product development, you need to determine whether you have the expertise to turn the product idea into a final product. The expertise needed may be related to the entire product or only a component. You can then start building knowledge based on the identified gaps through prototypes.
One technique to accelerate technology development is to define interfaces that allow you to isolate the technology development portion of your product. For example, to develop a smaller and lighter hand piece that still delivers that same power during use, there are 2 main choices: fully integrate the battery with the other hardware and software (like most smart phones today). The final product is smaller and lighter, but usually takes longer to develop because a change in one part often affects the entire product. The other option is to define the interface between the battery and the rest of the hardware/software. The final product may be a bit larger and heavier, but you have the ability to develop each independently and minimize the impact of changes to the rest of the product.
Technical prototypes are sometimes called engineering prototypes. You might make many different versions before you are satisfied that you have the right technology or approach. Thomas Edison is well known for the number of prototypes he created before finding one that could be used for a commercially successful electric light bulb.
Like customer prototypes, these often start out as rough approximations that are refined throughout development.
Manufacturing
A company needs to be able to manufacture the final product, so you want to include your manufacturing organization early in product development, before the design in finalized. Early prototypes can help identify design requirements which improve the success of the manufacturing process and reduce scrap. Lessons learned from manufacturing other products can also be incorporated to improved manufacturability.
Using a pilot line to assemble components can be a great way to build knowledge within manufacturing and provide prototypes which you can show to customer or use in testing. In general, manufacturing prototypes are more like the final product. However, use early mock-ups to check assembly processes for things like ergonomics, transfer between stations, etc.
Testing
Sub-assembly and final product testing can be completed using prototypes. However, you will need to document how the prototype is representative of the final product and what confirmation or new testing will be required to show the prototype data is acceptable. For example, your prototype used a 2 cavity mold but the production product uses a 12 cavity mold. If the materials haven’t changed, any material compatibility studies probably can be used, but you probably need to recheck molded product shrinkage, cooling, and stress points. Software can often define the code which needs to be retested when something changes or as it is integrated into another portion of the product.
Conclusion
Prototypes are a necessary part of product development that can be used in many ways including capturing user feedback, market acceptance, evaluating new technologies, testing for manufacturability, and evaluating performance. Prototypes can be used at any time during product development and often a portion of the product or idea (versus a final product) is good enough. Using prototypes can speed up product development because you have the ability to learn and adjust quickly.