Let’s cover the main types of prototypes made during product development, from rough models to functional and robust prototypes, and why accuracy in dimensions, surface finish, and properties is vital.
We provide practical tips for product development teams to follow, including clear communication with suppliers, understanding supplier capabilities, and the importance of detailed inspection and root cause analysis.
If you’re developing a new product, for example, a consumer electronic product, a mechanical device, or an electrical home appliance, this is invaluable advice to ensure your prototypes are as close to production-ready as possible.
Here’s a summary of some of the main points, listen for the full episode…
What are the 3 main types of prototypes during product development?
Most kinds of products, be they a consumer electronic device, mechanical product, or a home appliance, will generally need the same kinds of prototypes to be made during the development process.
- The rough prototype – The first prototype made from cardboard or styrofoam, for example, that gives you a rough idea of shape and size. Accuracy is not so important.
- A more refined dimesionally-correct prototype – Ensures dimensions and functionality within specification.
- A more robust prototype closer to production standard – Used for reliability, compliance, and durability testing, which do require a more production-intent prototype. (01:31)
Why is it so important to ensure you get the right parts with the right dimensions, the right surface finish, the right properties, etc, for your prototype?
The second type of prototype for functional and some other initial testing benefits from this, especially where there are mechanical components that move or parts that must fit together. For instance, for a simple gearbox, dimensional accuracy must be checked at this point to ensure that it will work correctly at an early stage. Sub-assemblies may be made and tested, and then all fitted together as functioning prototypes to test if they function holistically as the product.
Not every product R&D team has this testing mindset. They may be over-optimistic and rushing to ‘get things going’ rather than focusing on testing for what could go wrong. However, this could slow the project down overall due to extra iterations in the prototyping loop. (04:21)
What are good tips and best practices for product development teams?
- Produce enough information so your supplier understands what they should be delivering – This is more than just dimensions on a drawing, they need to understand the functional requirements, such as needing to be waterproof to a certain standard or resistant to certain environments. They may be experienced in materials and production, but can’t be left to second-guess your intentions for the product.
- Clarify the assembly conditions – Your supplier needs to know how accurate everything needs to be from a dimensional point of view, with geometric tolerances and surface finishes. Note that more complexity may increase prototype costs and the assembly conditions matter in some of the functional testing that may be required in your product.
- Material selection – Production will require certain materials or components to be used, but when prototyping using others that are perhaps just similar may be adequate at times to get working prototypes for testing as the areas using them aren’t as critical to be production-intent at that time and for those tests.
This confirms how important it is for the supplier to understand your requirements and understand which materials and components will be needed for prototypes. If you do not explain what you want to them, you almost certainly won’t get it. (07:15)
Communication with Suppliers.
You need to explain your requirements and give them some context.
Also work with them to determine exactly how things will be measured and tested, as then they can be made accountable for their results and also have the information and process needed to do the job and check independently.
Don’t assume that they fully understand (useful in China, for example). Everything must be exactly specified, as if the supplier is left to guess they probably won’t reach your expectations.
Keep communication channels open and speak regularly to build a good relationship. Scheduling regular meetings and visiting the factory to check that the project is going to plan is a great idea. You may also organize in-process inspections for extra peace of mind. (12:22)
Supplier Capabilities.
Be aware that you may not get the same results from a supplier who previously made one product if you’re using them to make a different product and its prior prototypes as this may not be within their capabilities or quality range.
Explore their following capabilities:
- Machining
- QC
- Team expertise
A specialist may be better than a supplier claiming they can ‘do everything.’ Fundamentally, you need to match your requirements to the supplier’s capabilities because if you end up with an unsuitable supplier you will not get the results you’re looking for. (14:35)
Importance of delivery
You need to ensure that you will receive the expected products when the supplier says they will deliver them. Can the supplier fulfill the deadlines they have been given? You need to keep communicating and one point of conversation should be their progress against the deadline/s. Even when they say they are ready to ship out your prototype parts, don’t accept them without an inspection report and something like a video or photos demonstrating the surface finish, etc. You need evidence that they are produced to specification. (17:05)
Incoming QC.
Every good or part, whether it’s going to be a one-off or a small batch of 10 or 15 for your prototype build,
that comes to you should be checked for quality to ensure that the dimensions meet the required specifications on the drawings that you supplied to start with.
Parts with issues can be found and sent back for rework or to be remade, so you don’t end up gathering everything, building the prototype, and then finding that a key component doesn’t fit, for example. So IQC is helpful if you want to keep your product development iterations shorter.
Obtaining parts that are right the first time is especially important if you’re planning to use that supplier for prototypes and scale up into production with them, too, as if there are problems for small quantities of prototype parts, those need to be solved before production can begin. (19:23)
Root cause analysis on defective parts.
If defective parts are found, before sending them back to the supplier for rework, etc, doing a root cause analysis will help to pinpoint the errors and put in place corrective actions. For example, you may have dimensionally correct parts that look fine on the surface, but they simply won’t fit together.
Just returning them to the manufacturer may not get a resolution. The cause of this confusing problem will require closer examination because they can’t be allowed to creep through to production parts. (23:28)
Finalizing prototype assembly and creating work instructions.
If you’re now building prototypes, we must get the functional prototypes functioning so we can analyze the product and tick off the boxes concerning the specification before we move into making more robust prototypes and design changes before we go into production as any issues found here that are not addressed will find themselves in production. Negative side-effects of not addressing issues during prototyping will be product recalls, negative reviews, and reputational damage. Perhaps even lawsuits if product faults cause injury or damage.
Supposing you have gone through all of the best practices mentioned, you’re ready to build prototypes with the parts in your R&D lab and there is a specific process to follow when looking at the product design and working out which components need to be fitted or assembled first and in which order.
This must be carefully documented concerning DFM (design for manufacturing) and DFA (design for assembly) as these notes can be translated into work instructions for when the product goes into pre-production (pilot runs, etc) and then mass production, with areas of concern highlighted for the operators to be made aware of. (25: 55)
Provide feedback to the supplier.
Once you’ve got everything built, tested, and running, provide some feedback to the supplier. If they deserve praise, give it. On the other hand, if there are areas of concern, discuss them. This will also help you to build a good relationship with them which is one of the best practices mentioned. (30:14)
A caveat for mass production.
There’s a caveat if you’re planning to scale up with a supplier from making a few prototype parts to going into mass production. Some suppliers are good at making a minimal number of parts, but when we start to scale up from 3 or 4 to 500, or even 2,000, say, they struggle for consistency.
This may suggest that they’re poor at managing their processes to have a consistent output over a series of tens or hundreds of thousands of parts. Ensuring they have the capabilities and capacity to scale up is also smart due diligence if this is the route you want to take. (32:50)