What is replacement?

Taking an AGL asset out of service and fitting a new one to do the same job, for example a new fixture, isolating transformer, cable section, sign or regulator. It renews the whole asset, as opposed to repairing a fault or renewing parts of the existing asset.

By weighing the asset's condition, its repair and failure history, the cost and disruption of each option, the availability of spare parts and manufacturer support, and the risk of leaving it in service. When repair or refurbishment no longer gives reliable performance at a reasonable cost, replacement is chosen.

A replacement has to do the same job in the same system. Its electrical rating, photometric performance and colour, mounting, connectors and interfaces must suit the circuit and the surrounding equipment, and an elevated fixture or sign must keep its frangible mounting and height. On a series circuit a different load or characteristic can affect the whole circuit, so an equivalent item is checked for compatibility before it is fitted.

On receipt, the item is inspected for damage and checked for the correct model, rating and identification. After fitting, the circuit and item are tested and commissioned, typically electrical checks, correct operation and, for lights, output and alignment where relevant. Acceptance criteria come from the manufacturer, the aerodrome procedures and the applicable standards.

It is made safe, removed and tagged, then handled through the decommissioning and disposal stages of the lifecycle. It should not go back into spares unless it is known to be serviceable. Where useful, failed items are kept for failure analysis.

The asset register is updated with the new item's identification and installation date, the old item's removal, the tests and results, who did the work and when service was restored. Warranty, spares and asset planning records are updated to match.