A 30-piece trial order across 10 SKUs is the smallest economically meaningful test of a new wholesale supplier. Build it wrong and you evaluate packaging rather than parts; build it right and you benchmark the bench-time savings against your current stock within a month.
The 30-piece template
| Model | Part | Pieces | What you learn |
|---|---|---|---|
| iPhone 11 | Battery | 5 | Capacity, BMS behaviour, popup warning presence |
| iPhone 11 | Charging port flex | 3 | Bracket fit, microphone test, gasket quality |
| iPhone 12 | Rear camera module | 2 | OIS calibration, connector seating, image quality |
| iPhone XR | Screen assembly | 4 | Brightness, True Tone behaviour, digitiser tightness |
| iPhone 7 Plus | SIM tray | 2 | Footprint precision, paint finish |
| iPhone XS | Battery | 4 | BMS behaviour on older generation |
| iPhone 8 Plus | Charging port flex | 3 | Cross-fit with 7 Plus, gasket feel |
| iPhone 13 mini | Sensor flex | 3 | HDI build, connector pad adhesion |
| iPhone 6s | Battery | 2 | Legacy support, compatibility claims |
| iPhone 14 Pro | Rear camera module | 2 | ProRAW pairing behaviour, premium module QC |
| Total | 30 |
What each line teaches you
- Batteries: BMS chip quality is the single biggest swing factor — test three with full charge-discharge
- Charging ports: bracket fit and gasket presence is the typical 80% failure pattern on cheap stock
- Camera modules: connector seating and OIS behaviour tells you whether the supplier sources from OEMs or aftermarket houses
- Screens: brightness at 100% True Tone on, and ghost-touch behaviour over a 24-hour bench soak
- SIM trays: 0.1 mm tolerance is the visible difference
- Sensor flexes: test Face ID and proximity sensor behaviour — the HDI build matters here
How to evaluate results
- Log every piece on arrival: defect rate, packaging quality, weight
- Run each part through the bench tests for its category
- Compare against your current supplier's same SKUs, side by side
- Decide on the basis of fail rate, not unit price — a 2% higher unit cost vanishes against a single comeback
- Place a Tier 1 reorder on the SKUs that passed; drop the SKUs that did not
Pitfalls to avoid
- All batteries and no screens: batteries are easy to evaluate; screens are the harder test
- All flagship models: legacy series generate equal walk-in volume and are unforgiving benchmarks
- Skipping the part the new supplier is most confident in: test your weak points, not their strong ones
After the trial
A successful 30-piece trial pulls in a Tier 1 reorder on the same mix, plus slow-mover SKUs from the broader catalogue. Browse the catalogue for the next round of SKUs to test. We ship trial orders same-day from Shenzhen via DHL — most buyers receive them within 4 working days.
FAQ
What if a SKU arrives damaged? Document with photos within 7 days; we credit the next order at the trial-tier pricing level.
Can the trial be smaller than 30 pieces? Yes — 10 pieces is the floor for a mixed evaluation, fewer than that and you cannot separate quality from packaging variance.