Additional drafting capacity is useful only if the downstream process can convert it into accepted files.
For a simplified hypothetical model, assume equal-complexity work, no losses between stages and capacity expressed on a comparable daily basis:
| Stage | Illustrative daily capacity or arrivals |
|---|---|
| Inspection-ready arrivals | 1,000 |
| Drafting | 1,500 |
| Supplier QA | 1,200 |
| Carrier acceptance | 800 |
The carrier acceptance stage limits throughput to 800 files per day. With 1,000 arriving daily, the queue grows by 200 per day, or 1,000 over five days.
Use this queue identity:
Closing backlog = opening backlog + arrivals − completed departures.
Then extend the model to include rework, different complexity bands, missing inputs, absence, system interruptions and provider allocation across clients.
Ask the supplier to demonstrate:
- Reserved versus merely available capacity.
- How QA staffing scales with production.
- Training and calibration for additional workers.
- Allocation rules when several clients experience the same event.
- Overflow providers and shared infrastructure dependencies.
- Maximum sustainable output, not just a one-day peak.
- Backlog recovery after the surge.
Measure quality and review effort during the test. Do not accept a surge plan whose principal mechanism is relaxing the acceptance standard.