Building the Right Prototype: 3 Steps for Creating the Perfect Prototype Plan
A thoughtful prototyping strategy will ensure your product is developed as quickly and efficiently as possible.
Product development teams often need to build several prototypes to move from product idea to product launch. While simple prototypes can be designed and built quickly, more advanced prototypes require substantial design and fabrication time. A development project will suffer unnecessary costs and schedule delays if prototype efforts are not carefully planned.
How do you determine the right prototype?
First, some background. The word “prototype” is used broadly in product development. It can describe a simple mock-up of a single feature on a product (a feasibility prototype), or it can refer to something that nearly replicates the appearance and functionality of the final product (a production representative prototype). Or, it can be anything in between those two extremes.
Prototypes are used to test ideas, prove out designs, and make critical decisions when developing a new product. While engineering calculations and computer modeling are important, prototypes are the best way to learn if your product will work as envisioned.
With those things in mind, here are three steps to ensure your prototyping efforts are as focused and efficient as possible:
1. Get Specific on the Questions your Prototype will Answer
Make a list of the specific questions you want your prototype to help you answer. Seriously, write them down. Usually, this list should include no more than three questions for a single prototype design. Otherwise, you may be trying to accomplish too much with one prototype.
Address the questions that have the highest technical risk and are most impactful to the product design as early as possible in the project—these questions are often core to the functionality or usability of the device. In many cases, questions about manufacturability and durability are lower risk and are addressed later in the project. They are often commonly solved or are unlikely to become an issue. Thoughtfully prioritize questions by risk level and design impact to decide which questions should be answered by building a prototype at each stage of development. You will need to build several prototypes along the course of a development cycle that will answer the range of questions you have.
Prototypes are built to answer different types of questions throughout the product development process. Here are a few examples:
Do consumers prefer a new smartwatch design with the face on the inside or outside of the wrist and with touchscreen or push-button controls?
Which of two concepts for a new dashboard phone mount will most effectively hold cell phones of various sizes?
Will an innovative design for a non-contact body temperature thermometer accurately measure body temperature?
Does a new sports headphone design meet all the product requirements, such as sound output, water resistance, and blue tooth range?
Does a new portable ultrasound diagnostic tool enable doctors to reliably detect tendon inflammation as intended?
2. Plan Your Evaluation Methods
The test methods you use to answer your questions will greatly affect the type of prototype needed to conduct the evaluations. Therefore, it’s important to determine evaluation methods before you spend the time to design and build a prototype. The examples below illustrate how evaluation methods influence prototype design:
User Studies
To determine consumer preferences for the wrist position and user controls for a new smartwatch design, you will likely want to conduct a user study. Simple, non-functional prototypes that represent the size and shape of different smartwatch designs would be perfectly adequate for users to determine if they prefer the face position on the inside or outside of their wrist. Additionally, off-the-shelf smartwatches could be used to let users in the study actually try touchscreen and pushbutton controls to decide their preference – no new prototype needed.
Core Functional Evaluation
To determine if an innovative, non-contact body temperature thermometer accurately measures body temperature, you may be able to use a prototype that has little resemblance to the final product. For example, a prototype of the working temperature measurement elements – sensor, electronics, and power source – could be used to assess measurement accuracy. The prototype likely doesn’t need to include the housing or user controls that the actual product will have.
Engineering Confidence Testing
Conversely, many evaluation methods will be needed to determine if a new sports headphone design meets all its product requirements, including sound measurements, underwater tests, and so on. In this case, it is necessary to build prototypes that represent the actual production version of the headphones to be confident of the evaluation results.
3. Define Your Prototype’s Design and Build
Now that you have defined your questions and planned how you will evaluate your prototype, you need to determine the type of prototype to design and build. The key is to define the prototype design and fabrication method that both enables you to answer your questions and minimizes the schedule and budget.
Non-functional Mock-Ups to Compare Design Concepts
In the case of the smartwatch, non-functional wearable prototypes of different face configurations will allow a user in a study to compare designs, but the functionality and final appearance of the watch are not needed.
Rough Prototype with Emphasis on Technical Feasibility
For the thermometer measurement accuracy assessment, your question and your evaluation method are very focused on temperature measurement accuracy. This requires only a rough prototype to evaluate technical feasibility. These prototypes often look nothing like the final product and can be made from modified off the shelf products, machined parts, or simple 3D printed parts.
Engineering-Confidence Prototypes to Verify your Product Requirements
As the project progresses to detailed design, an advanced prototype is needed to verify that the design will meet the product requirements. In the case of the sports headphones, you would want final electrical components so you could accurately measure sound output and Bluetooth range, and the mechanical build would need a production equivalent seal in order to test water resistance. If your final product has an injection molded housing that is glued together, it might be okay at this stage to machine your housing components, but with a glue joint that represents the plan for the final product as this is critical to your confidence that the final product will be water-resistant.
This type of prototype will most closely resemble your actual product. It might have a different color or texture, and may be devoid of final branding, but the shape, components, and assembly should be as close to your intended production design as possible.
Ready, Set, Go!
With your questions clearly defined and your evaluation methods chosen, you can be confident that you are building the right prototype at every stage of your development project.