Componentization: How to Depreciate Complex Assets by Part

An airplane is not a single asset. It is a fuselage that lasts 25 years, and jet engines that require complete replacement every 5 years. If the airline depreciates the entire aircraft as a flat uniform asset over 20 years, their depreciation expense will be wildly incorrect, and replacing an engine will plunge the register into chaos.

Componentization is the accounting practice of breaking down a large asset into its significant parts, tracking them individually, and applying unique depreciation rates to each. It is a strict requirement under IFRS and GRAP for major infrastructure.

Commercial real estate is the most common target for componentization. A R50 million building should be split into the roof (15 years), the elevators (20 years), the HVAC systems (10 years), and the core shell (50 years).

Tracking these independently means that when the HVAC system is ripped out and replaced after a decade, the old component can be cleanly retired and written off, and the new HVAC component can be onboarded without impacting the depreciation schedule of the roof or the concrete shell.

Software handles this via parent-child asset relationships. The parent asset (Building A) acts as a structural container that holds the child assets (Roof, Elevator, HVAC). The physical verification team audits the parent, but the finance team depreciates the children.