Link every circuit board, firmware load and acceptance test to the unit serial.

Avionics units are built in low volumes with long lead times and strict control of what goes inside. One connector may be on allocation for months. A substitute needs approval.

This software records the build of each unit as a chain. Board lot, components with date codes, solder profile, firmware load, burn-in and test results attach to a serial, and later repairs add to the same chain.

Purchasing orders from approved sources only. Goods inward checks the date code, lot and packaging of every reel and tray. Moisture-sensitive parts are baked or sealed according to the time they have been exposed to air on the shelf or on the line. Kitting prepares a set for each board lot against the bill of materials at the current build standard.

On the line, boards go through paste print, placement and reflow, then inspection under optical and X-ray cameras before any through-hole parts, harnesses or conformal coating are added by hand. Each unit is then loaded with its firmware and put through burn-in and an acceptance test procedure.

Failures are logged with the fault, the part replaced and the operator. Passed units are boxed. A certificate goes in. Units returned for repair are tested again and brought to the current standard.