Testing, honest.
In context: Stage 08 · Develop · sub-stage Start: Testing
The point where the prototype stops being your opinion and starts answering to buyers, standards and the way it gets used.
The Testing sub-stage of Develop puts the prototype in front of real users, real comparisons and real standards. Run focus groups, A/B tests, fit and function checks, user testing and the CE/UKCA route. Find the faults here, cheaply, before tooling makes them expensive.
What the Testing sub-stage is
This is where Develop gets ruthless. Testing is the deliberate effort to break the prototype on purpose, in front of the people and the rules it will eventually meet. The job is not to admire what you have built. It is to expose what is wrong while changing it still costs hours, not tooling.
In my experience the products that skip this stage do not skip the failure; they just move it downstream to where it is far more expensive. A snag found in a focus group costs an afternoon. The same snag found after the Stoke ceramic mould is cut costs a great deal more, and the buyer finds it for you.
For the £149 proofing box, this is where Dan and Anna Hartley handed prototypes to bakers around Stockport and the Sourdough School audience. We checked it really held 26°C ±0.5°C in a cold kitchen, confirmed the Manchester PCB stayed under 30W, and watched people use it without an app. What we learned reshaped the lid before anything was committed.
What’s in this sub-stage
Five activities take the Testing sub-stage from a working prototype to evidence you can manufacture against. Work them roughly in order.
How it fits the bigger picture
Testing follows the Prototypes sub-stage of Stage 08 Develop. It takes the physical prototype and pressure-tests it against buyers, comparisons and standards, then feeds a proven, conformant design into Stage 09 Manufacture. Test it well here and Manufacture inherits something trustworthy; skip it and you tool up around faults that surface only once units ship.
What it can do
It surfaces the faults, the misreadings and the conformity gaps while they are still cheap to fix, and it replaces your conviction with evidence from real users and real standards. Done well, it ends with a design you can hand to manufacture with confidence and a clear record of what was checked.
What it can’t do
It can’t guarantee commercial success; a product can pass every test and still struggle to sell. And it can’t fix a weak concept. Testing tells you the truth about what you built, but it cannot turn the wrong product into the right one.
See the full 10-stage process →
Try it yourself
Take your own prototype and put it in front of five people who fit your buyer, then say nothing and watch. Note every hesitation and every moment they used it differently from how you intended. Those notes are your test backlog.
Or run the guided version. The Free Sprint covers the early stages; deeper testing tools sit in the paid ladder. Start the Free Sprint →
— First in Testing → Focus group test