Every laptop, server, and monitor your organization owns loses value over time. Accounting knows this. IT usually doesn't track it. The result: finance maintains a separate spreadsheet of asset values, IT maintains GLPI's inventory, and the two never agree. GLPI has built-in depreciation tracking that can bridge this gap -- if you configure it and keep the financial data populated.
How depreciation works in GLPI
GLPI uses straight-line (linear) depreciation. Configure two parameters per asset type in Setup > General > Assets: the depreciation period (in years) and the depreciation coefficient (typically 1 for standard linear). Set different periods for different asset types -- 3 years for laptops, 5 years for servers, 7 years for network infrastructure. GLPI then calculates the current book value based on purchase date and purchase cost.
Setting up the data
Depreciation calculations require three data points per asset:
- Purchase date -- when the asset was acquired
- Purchase cost -- how much was paid (excl. VAT for most accounting purposes)
- Asset type -- which determines the depreciation period
This is where most GLPI installations fall short. The inventory has serial numbers and locations, but the financial fields are empty. Without purchase cost, depreciation is just a countdown timer with no monetary value attached.
If you're starting fresh, make purchase cost a mandatory field for new assets. For existing assets, work with finance to backfill the data -- a CSV import via GLPI's data injection plugin can handle this in bulk.
Current book value calculation
Once configured, GLPI calculates the current book value automatically:
Book value = Purchase cost - (Purchase cost / Depreciation period in months * Months since purchase)
When the depreciation period expires, the book value reaches zero. The asset is "fully depreciated" -- it still works (hopefully), but its accounting value is nil. This is the trigger for replacement planning.
Building a hardware refresh forecast
Use GLPI's search engine to build a query: all computers where the depreciation end date falls within the next 12 months. Export this list. You now have a hardware refresh forecast grouped by:
- Asset type (laptops, desktops, servers, monitors)
- Department or location (which teams will need new hardware)
- Estimated replacement cost (based on current purchase prices for equivalent models)
This list is your capital expense forecast for IT hardware. Hand it to finance before the fiscal year starts. No surprises, no emergency purchase requests.
Connecting depreciation to ticket data
If your tickets are linked to assets (as they should be), you can cross-reference depreciation status with support costs. A laptop that is 80% depreciated and generating two tickets per month is a clear replacement candidate. A fully depreciated server running without issues might be fine for another year. The combination of depreciation data and ticket history gives you a fact-based replacement priority list, not a guess based on age alone.
Common gaps and how to fix them
Purchase costs not entered
The most common problem. Without cost data, depreciation tracking is meaningless. Solution: make it a mandatory field and do a one-time backfill from accounting records.
Inconsistent asset types
If "laptop" and "notebook" and "portable computer" all exist as separate types with different depreciation periods, your calculations will be inconsistent. Standardize asset types and merge duplicates.
Warranty vs. depreciation confusion
Warranty expiration and depreciation end are different dates serving different purposes. A 3-year warranty on a 5-year depreciated asset means warranty coverage ends while the asset still has book value. Track both -- warranty expiration triggers a support risk assessment, depreciation end triggers a financial planning action.
Depreciation tracking directly answers the question every CIO faces annually: "How much do we need to spend on hardware next year?" The answer is already in your data. It just needs to be configured, populated, and read.