Where the pilot run fits
In the EVT, DVT and PVT sequence, the pilot run usually corresponds to PVT, the production validation build.
By the time of the pilot run, the design should be frozen, tooling approved after mold trials, and certification testing complete or close to it. A pilot run used to find design problems is a late and expensive engineering build.
Timing also has a materials side. Long-lead components for the first production orders often have to be ordered before the pilot run is finished. Decide in advance how much material you are willing to commit at risk, and which pilot results would make you hold or cancel those orders.
What factories call it
The same build goes by several names, and the same name can mean different builds. Agree the build conditions in writing rather than relying on the label.
| Term you may hear | What it usually means | What to confirm |
|---|---|---|
| Trial run, trial production (试产, shìchǎn) | Any early build in the factory before mass production, from a DVT build on early tooling to PVT | Which stage, which line and which tooling |
| Pilot run, small-batch trial production (小批量试产) | The first build under production conditions, usually PVT | Quantity, operators and exit criteria |
| Pre-production (PP) | At some factories, a build after PVT to confirm fixes or make launch stock | Whether the pilot exit criteria still apply |
| Mass production (MP, 量产, liàngchǎn) | Released volume production | That the release decision was made and recorded |
What a pilot run should prove
- The line can run at a realistic rate, with balanced stations and measured cycle times
- Fixtures and test stations work, with stable first pass yield at each station
- Work instructions and inspection criteria are complete, and operators can follow them
- Every supplier delivers materials on time and at the right revision
- Packaging, labels and cartons work, including transit or drop testing
- Traceability works from component lots to serial numbers
- Outgoing inspection, often against an AQL sampling plan, runs as planned
How big should a pilot run be?
Large enough to run the line at realistic speed for long enough to see stable yields and real failure modes. A few dozen units assembled slowly by engineers does not test the process. For consumer electronics, pilot runs are often in the hundreds of units or more, but the right size depends on the product, the planned production rate and how many stations need to be exercised.
Units built to the released revision on the final process and passing every test are often sellable, which offsets part of the cost. Agree that before the build, and keep units built with temporary fixes or deviations out of sales stock.
Exit criteria
Write these down before the build, each with an owner:
| Area | Exit criterion |
|---|---|
| Yield | First pass yield per station at or above the agreed targets |
| Defects | Top failure modes understood, with corrective actions in place or scheduled |
| Process capability | Cpk on critical dimensions or parameters at the agreed level |
| Test | Test programs, limits and fixtures released |
| Documentation | Work instructions, inspection criteria and golden samples signed off |
| Materials | Supply of long-lead parts for the ramp confirmed |
| Packaging | Packaging and transit tests passed |
| Compliance | Certifications complete, or remaining items scheduled before shipment |
The pilot run report
A pilot run should end with a written report that both sides sign. At minimum it records:
- Quantities started, passed, reworked and scrapped at each station
- The failure Pareto, with analysis of the top failures
- Measured cycle time at each station against the plan
- Deviations: anything built differently from the released documents, and why
- Material problems: shortages, wrong revisions, supplier quality issues
- An open issues list with owners and dates, and the decision on the next step
The pilot production run guide covers build sizing, line readiness and defect tracking in more depth, with the evidence behind each exit criterion. Mass production ramp-up covers what follows a successful run.
Where Zefinity helps
Prototype and pilot production coordination is part of Zefinity’s Connect service, and production readiness and ramp-up is part of Launch.
Frequently asked questions
Who pays for a pilot run?
Usually the buyer, through a purchase order for the pilot quantity, often at the production unit price or a separate pilot price, plus any line setup, fixture or test costs quoted as NRE. Some suppliers include one pilot run in their NRE and charge for repeats. Agree in advance who pays for a second pilot run if the first fails, which normally depends on whose problem caused it.
Should the brand have someone on the line during a pilot run?
Where possible, yes. An engineer or quality lead from your side, or someone acting for you, sees what a summary report leaves out: units reworked at the station, parts sorted before they reached the line, tests rerun until they passed. Agree access before the build, including which records you can review each day and who has the authority to stop it.
What happens if the pilot run fails?
It depends on what failed. A design problem sends the product back to engineering. A process problem usually means fixing the cause and running a second pilot, or ramping slowly with containment such as full inspection. Each option costs time, but all of them cost less than launching a process that is not ready.