4 Types of Pre Production Prototype You’ll Make Before Production

4 Types of Pre Production Prototype You’ll Make Before Production

For most electro-mechanical products, these are the main 4 types of pre production prototype (that are often called “final prototypes”) you’ll make before production can start. They actually represent helpful milestones for your project. Let’s look at what they are, when they’re made, and the differences between them here.

We excluded the intermediary stages such as the “initial proof-of-concept” that demonstrates 1 or 2 of the main functions, the “purely look alike”, and the “purely work alike” prototypes, as they are usually not qualified as “final”. Our main point here is, many different pre-production samples can be called “final”, and that can be confusing.

By the way, I’m assuming that the product has a custom-designed enclosure that is made of plastic.

 

When these pre production prototypes will be made during the NPI process

Before we start looking at your four final prototype options, here’s when you’ll be making them during the new product introduction process:

Pre Production Prototype Type 1: A few work-like and look-like prototypes (before tooling)

Approval of this prototype is a very important milestone. It means the time has come to confirm and freeze the product design and to work only on the manufacturing & testing processes. (Note: when timelines are very tight, it may make sense to take risks and to have some engineers keep working on improvements past this stage, but generally it is not recommended.)

This is important for companies that want to launch their product on Indiegogo and especially Kickstarter.

This iteration of your prototype can go through highly accelerated life testing (HALT), to find out what its weaknesses are and confirm that none of them are so pronounced it jeopardizes success in the marketplace.

It is not, however, the “golden sample”. The appearance will be different once the custom parts come off the tooling as they’re not made using production processes and tooling.

Typically, the plastic parts will have an injection gate, flow line(s), etc. It is quite important to plan for those at this stage, as they might make the product unappealing and reworking an injection mold can be costly in time and money.

At this point, there is still a long way to go for a relatively complex product or a device with safety-critical considerations; even if you have followed good “design for manufacturing” practices.

 

Type 2: Tens of final prototypes (before tooling)

Customers often request 10, 20, or 50 pcs at this stage for various reasons:

  • Get final feedback from end customers, and ideally pre-sell a larger amount of products to a distributor or a B2B customer
  • Conduct accelerated life tests to confirm product reliability & durability
  • Send to a compliance laboratory for testing (note: this makes sense in some cases, but not in others — for example, EMC testing for FCC or CE RED/EMC certification needs to be done on the exact final production product, and plastic parts that are 3D printed or CNC machined don’t have the physical properties of molded parts)

The prototypes are typically still assembled by a few engineers on a bench at this point.

 

Type 3: Tens of final prototypes (with parts coming off tooling)

They represent the “final look” of the product, and they are often the source of the “golden sample“. It is an output of the DVT stage (Design Validation Testing).

Approval of these final prototypes is an important milestone. Along with other indicators, it is a sign of readiness to go to the next step (which we call pre-production preparation, and many companies call PVT — Production Validation Testing).

This is, in many cases, the most suitable time to send samples to a compliance laboratory for testing. And, if estimating the expected lifetime of the product is important, a ‘life test’ is arranged at this time.

Altogether, that means a lot of samples need to be sent to labs for various types of tests. We covered it before:

Here’s an example (based on a real case) of the sample prototypes needed for the different tests of an electronic device to be imported into the USA to give you an idea of what’s required:

8 units for FCC/CEE (ionizing radiation/energy efficiency)
2 units for ESD (electrostatic discharge)
23 units for various reliability tests
5 additional samples to be held in reserve in case they’re required for reliability testing and ESD.
3 boxes full of finished products for ISTA-2a transportation testing (packaging reliability testing) which will drop, vibrate, and shock the whole box [note: only if packaging protection is important]
So that’s a total of 38 sample prototypes plus however many are inside three boxes.

In most cases, this is still an engineering build. It is not done on an assembly line. Everything is slower, more manual, and less systematic than in PVT or in mass production.

 

Type 4: Tens or hundreds of production products

In the PVT phase (before mass production), tens and then sometimes hundreds or even thousands of products are made. This is what many people call the pilot run.

The custom parts are made with the production-intent processes. The assembly, testing, and packing stations are ready. The operators and other staff have been trained. Process and quality engineers are involved in finding and fixing the big issues that invariably come up on a new product, one by one.

It is not “mass production” yet. The proportion of the products that are “good the first time without any rework” (aka first pass yield) is not very high. Productivity may be lagging. There is a lot of fine-tuning to do.

The final prototype samples at this point will typically be sold if they pass final testing & inspection.
(In some cases an in-depth reliability testing program leads to the deterioration of many of those samples, so those cannot be sold.)

Many defects can be caught at this point, and it is a good time to start collecting some limit samples.

 

Conclusion

During the process of designing and developing your new product to take it from concept to mass production, you can see that you will need to create quite a number of pre production prototypes that are used for various purposes such as reliability and compliance testing (which necessarily leads to the destruction of some).

An important message here is that rushing from your first pre production prototype where you have locked the product design to mass production is risky because there’s a very large difference between making one good prototype product and mass-producing thousands of them all reaching the required quality standard. I covered this point in more detail in: Going from 1 Prototype to Mass Production directly is Dangerous.

So, budgeting for these prototypes is one of the NRE costs that you need to account for early on in the project if you want to keep control of costs and have the samples required to go through a thorough NPI process which gets your product on shelves with the fewest risks of quality, safety, and compliance issues possible.

If you have any questions about prototyping or bringing your new product to market in general, do let us know by contacting us! 😊 

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