Skip to content
AQUASEE

supply chain · general

Quality control across the production chain: what to check, and when

End-of-line inspection finds problems after they have been paid for. Inspection at agreed milestones — material, first article, in process, pre-shipment, site acceptance — finds them while they are still cheap to fix.

7 min read · updated 2026-10-24

The principle

Quality is not a stage at the end of production; it is a sequence of checks placed where a defect can still be corrected cheaply. The later the check, the more expensive the correction — and the more likely it is that the correction is a rework rather than a repair.

This is why the inspection regime is written into the contract at the same time as the specification, not after the first problem appears.

Five stages

Each stage answers a different question, and each one has a document.

  • Material and preparation — is the grade right, and was the surface prepared as specified?
  • First article — does the first production unit match the specification, in a way the main run can repeat?
  • In process — is the work still on the approved method, and are the changes controlled?
  • Pre-shipment — is the complete set correct, packed, protected and documented?
  • Site acceptance — does it match the specification in place, under real conditions?

Why the first article is the most important check

The first article is not a sample; it is the first unit of production, inspected against the specification before the run is released. It answers the only question that matters at that point: is the process capable of making the rest?

A first article that passes without a difficult conversation about finish, fit or tolerance is the strongest evidence available that the remaining units will be right. Skipping it to save a week is the most expensive shortcut in production.

Inspection records are not paperwork for their own sake. They are the evidence that makes a later conversation about a defect a factual one.

What the records must contain

The handover pack should contain the inspection records, the material certificates, the approved drawings and the revision history, and the change log. Together they answer the question that comes up in year two: was this the way it was supposed to be built?

Without them, every warranty conversation becomes an argument about memory.

Sources