A prototype proves that the design works. A pilot run proves that the factory can make it with production tooling and methods. Mass production delivers the volume, at a consistent quality. Each stage answers a different question, and skipping one usually moves the problem into a later, more expensive stage.
The names vary between companies, but the logic is the same in every engineering business.
Prototype
Prototypes are often made by hand or machined from solid, without final tooling. A cast part may be machined from a billet. A sheet metal part may be laser cut and bent by hand. The goal is to test fit, function and appearance quickly.
Prototypes are not proof of production quality. They are made slowly by skilled people, often on toolroom machines. A perfect prototype does not mean the production part will be perfect.
Use the prototype stage to test the design hard. Fit it into your assembly, run it under load, and show it to your customer. Design changes are cheap now and expensive once tooling is cut. Record every change on a new drawing revision so the pilot run uses the right version.
Pilot run
A pilot run uses production tooling, production machines and production staff. It is usually a small batch, large enough to show variation. This is where you find out whether the process is stable.
- Production tooling such as patterns, dies and fixtures is used for the first time.
- A full dimensional report is made, often as a first article inspection.
- Capability on critical dimensions can be measured from the batch.
- Packing and labelling can be tested before the first full shipment.
- Problems are fixed before large volumes are made.
Mass production
Once the pilot is approved, production runs at full rate. Quality now depends on control: inspection at set intervals, calibrated gauges, stable material sources, and no unapproved changes. Many buyers find that quality slips after the first container, for reasons explained in why quality drops after the first container.
Agree how changes will be handled before production starts. Any change to material, process, tooling or subcontractor should be notified to you and approved. See design changes during production.
How much time to allow
For a simple part, all three stages may take a couple of months. For a new machine or complex assembly, the prototype stage alone can take that long. Build the stages into your plan and contract, with approval points between them.
Do not pay for full tooling before the prototype is approved if the design may change. Do not order full volume before the pilot is approved.
Next step
We follow each stage at the factory and check samples before you approve them. Book a free sourcing review.