The Three Phases OfProduct Prototyping Part2

Common Product Development Mistakes

Many engineers approaching a project for the first time make common mistakes when approaching the process. These typically include:

They don’t ask for advice on how to plan ahead or get beyond the first few iterations of the prototype.

Not asking what the next steps after the next steps will be no accurate estimate

They don’t show their prototypes to the end user soon enough and want to hide their ideas from their customers until they are “perfect”.

They don’t make enough prototypes to get into the hands of multiple users. Design, idea and customer feedback is incredibly valuable.

The design of the prototype is not developed in conjunction with the physical prototype itself. There is a lot to be learned by observing how people use products naturally or misuse them because they aren’t intuitive or don’t give the right cues.

Most new developers are curious how long the whole process will take. The answer is that this varies wildly depending on product complexity, industry affiliation, certification requirements, etc. In general, it can take anywhere from six months to two years from idea to product launch. For medical devices, for example, it typically takes longer (3 to 5 years) because additional certifications and approvals are required.

3D Printing: A False Sense Of Security

3D printing is undoubtedly an amazing technology. The intricate shapes that can be created with 3D printing, while impressive and practical, can give inexperienced engineers and designers a false sense of security about the success of their designs.

When using 3D printing during the prototyping process, it is important to always remember that you will ultimately have to manufacture the components you design using alternative, conventional manufacturing processes. We’ve seen many designers take their 3D printed designs to the point where they wanted to start manufacturing, and then have had to completely redesign their products because the components couldn’t be mass-produced, with serious consequences pulled. It is crucial to design the process that will be used for the prototype and how it will ultimately be manufactured.

Also, the strength, stiffness, and tolerances of 3D printed materials can differ significantly from those produced, which can lead to errors if not planned in advance.

Later in the product development cycle, two different product designs are often worked on in parallel. A version of the product design is used for prototype testing and design validation. The other design is then destined for mass production. This concurrent engineering approach, while resource intensive, offers the lowest risk and shortest time to market.

The Three Phases

As we have already established, the whole prototyping process can be divided into three phases. These phases roughly correspond to a progression along the TRL (Technology Readiness Level) scale, as the following graphic shows:

Let’s take a closer look at each phase to gain a deeper understanding of the prototyping process.

I: ALPHA PHASE

The alpha phase represents the first iteration of prototypes and is primarily concerned with answering two questions:

Will the product work?

How will it look and feel?

Answering these questions usually necessitates two separate prototypes, each one specifically created to address basic functionality and user experience respectively. We can refer to these first two as the proof of concept and the appearance prototypes.

Proof Of Concept Of Prototype

The first physical model created as part of product planning is the prototype to test the concept. It was designed to answer the question “Will it work?” to answer, and is strictly focused on function rather than form, so it will have little to no resemblance to the final product.

This functionally representative prototype uses readily available materials to simulate the physical form and uses standard technologies to manufacture the individual components. These materials can be:

Cardboard, tape, foam and wood to show physical properties

Hardware such as pumps, motors and heaters to simulate mechanical functionality

Ultimately, this prototype is suitable to validate the functionality of the product and to be tested in a variety of controlled environments.

It is a formative stage in the product development process where the viability of the product is quickly established and a rapid succession of systematic testing is performed to verify assumptions, rule out potential flaws and understand if there really is a market for the product, what also known as product/market fit.

Appearance Prototype

After a convincing result has been achieved in the proof of concept phase, the prototype of the appearance usually follows. This model answers the question “What will it look and feel like?” and offers a preview of the final design.

The appearance prototype is visually representative but has no actual functionality. It’s a static model with no working features, just to give you a feel for how it looks and feels.

With the use of CNC machined parts and 3D printing, more effort is expended to create a prototype that resembles the look of the final product. Also, higher quality materials are used in this phase to simulate the user experience.

Materials used typically include:

• 3D printed plastics
• CNC-machined RenShape, medium-density fiberboard (MDF), solid wood, foam and clay
• CNC milled or lasered/punched sheet metal
• Color

At this stage, engineers try to find a balance between using viable materials and using inexpensive ones, since prototyping can cost 50 to 100 times more than the final mass-produced product.

This prototype is also commonly used for sales and marketing purposes, as well as raising funds and investments. Because it physically represents the end product, potential buyers and other stakeholders can get an accurate picture of it.

In some situations, prototypes can also be used as a proof of concept. It depends on the product and the situation.