A New Zealand company needed its handheld water-testing device ready for a seasonal sales window. Planned prototype loops, each answering specific questions, cut development from 23 to 14 weeks and tool modifications from seven to one.
Key numbers
A New Zealand company developing a handheld water-testing device faced a hard deadline: a seasonal sales window that would not wait. Its previous product had taken 23 weeks to develop, with six prototype loops and seven tool modifications after production tooling was cut. Repeating that would mean missing the season.
The situation
The device needed to be ergonomic, drop-resistant and sealed against water, all in a compact housing with electronics and a sensor. Each of those requirements had caused problems on the previous product, discovered late, mostly after tooling.
What changed
The development plan was built around a simple principle: every prototype loop must answer specific questions, using the cheapest method that answers them credibly, the approach described in prototype or simulate.
- SLA prototypes for form and ergonomics, tested with real users in the first weeks.
- CNC-machined parts in production-grade material for functional testing: snap fits, seal compression and drop behaviour.
- A soft tool producing 200 parts in the production material for field trials, revealing moulding and assembly issues before production tooling.
- A design FMEA run on the sealing, drop and battery functions, in the way described in design FMEA.
- A full DFM review completed before production tooling was released.
What the data showed
Compared with the previous product, every phase was shorter. Concept fell from three weeks to two and detailed design from six to five. Prototype and test fell from eight to six weeks, because each loop had a clear purpose. Tooling corrections fell from six weeks to one, because the problems had already been found and solved.
Results
Development took 14 weeks instead of 23, a reduction of about 40%. Prototype loops fell from six to four. Only one minor tool modification was needed, compared with seven on the previous product. The device launched in time for the seasonal window.
Why it worked
The time was not saved by working faster. It was saved by finding problems earlier, when they were cheap and quick to fix. The soft tool in particular paid for itself several times over, by revealing real moulding and assembly issues before production steel was cut.
Lessons for your operation
- Plan prototype loops around questions, not around "the next version".
- Match the method to the question: printed parts for form, machined parts for function, soft tools for moulding reality.
- Problems found before production tooling cost days; problems found after cost weeks.
- A DFM review before tool release is the cheapest schedule insurance available.
