Prototypes, built.

In context: Stage 08 · Develop · sub-stage 08.10

Where the design stops being a model on screen and becomes progressively more real, from looks-like mock-ups to first units off tooling.

— TL;DR

The Prototypes sub-stage builds the product in stages of increasing realism: a physical model, then proof of concept, presentation, functional and pre-production prototypes, ending with a production prototype. Each one answers a different question before you commit to volume.

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What the Prototypes sub-stage is

This is where Develop gets physical. You take the engineered design and build it for real, in a sequence of prototypes that each get closer to the finished product. The job is to surface problems while they are still cheap to fix: a looks-like model tests form and feel, a functional prototype tests that the thing actually works, and a production prototype proves it can be made the way you intend to make it. Each step answers its own question, and you do not skip ahead until the current one passes.

For the £149 proofing box, this sub-stage is where Dan and Anna’s design left the screen and became things I could pick up. We built a foam-and-resin looks-like model first to check the tub felt right in the hand, then a rough functional rig that held 26°C reliably, then a presentation model that looked the part. Only once the Stoke-on-Trent ceramic and the Manchester PCB came together in a pre-production unit did we trust it against UKCA and the BS EN checks.

What’s in this sub-stage

Six prototype types take the Prototypes sub-stage from a first rough model to a unit off production tooling. Work them roughly in order.

Physical model prototype

A looks-like model that lets you judge form, size and feel in the hand before any function.

Proof of concept prototype

A rough rig that proves the core idea works at all, with looks and finish set aside for now.

Presentation model

A high-finish model that shows the product as it will look, for buyers, investors or reviews.

Functional prototype

A working unit that does what the product is meant to do, so you can test it for real.

Pre-production prototype

A near-final build using close-to-final parts and processes, to flush out the last issues.

Production prototype

A unit made on the real production tooling and line, proving the product can be built as planned.

How it fits the bigger picture

Prototypes is part of Stage 08 Develop. It takes the detailed work from Stage 07 Engineer and turns it into real, increasingly finished hardware, ready for the testing sub-stage that follows. Get the prototype sequence right and testing has solid units to push hard; skip steps and you end up testing problems you could have caught earlier and cheaper.

What it can do

It turns the engineered design into something real you can hold, run and show, catching form, function and manufacturing problems at the cheapest possible point. Done well, it ends with a unit that can be built on production tooling and trusted to perform.

What it can’t do

It can’t tell you whether the product survives real-world use over time; that is the testing sub-stage’s job. And it can’t fix a weak design. If the engineering inputs are flawed, the prototypes will faithfully reproduce the flaws.

See the full 10-stage process →

Try it yourself

Take your own product and decide which prototype you actually need first. Most people jump to a pretty model when a rough proof of concept would answer the real question faster and cheaper. Write down the one question each prototype must answer, then start with the first activity below.

Or run the guided version. The Free Sprint covers the early stages; deeper development tools sit in the paid ladder. Start the Free Sprint →

— First in Prototypes → Physical model prototype