Planned (or preventive) maintenance is work done on a schedule to keep assets safe, compliant and working: inspecting, testing, cleaning, replacing parts. Each asset type has a regime: a set of tasks with frequencies and skills. In the UK, SFG20 is the widely used standard library of these regimes. BIM's job is to make sure every maintainable asset arrives in the maintenance system linked to the right regime.
At a glance
| Users | Maintenance managers, FM contractors, compliance managers, engineers |
| Regime | Tasks (what), frequency (how often), skill (who), criticality (how important), compliance reference |
| Standard libraries | SFG20 (UK, published by BESA), manufacturers' recommendations, owners' own schedules |
| Where regimes run | The CMMS, which creates work orders from them |
| BIM's role | Each asset tagged, located and typed so it can be matched to its regime |
Statutory, manufacturer and optional
| Category | Example | Why it matters |
|---|---|---|
| Statutory | Fire alarm tests, emergency lighting tests, lift inspections, gas safety | Required by law; missed tasks are legal risk |
| Manufacturer | Filter changes, belt checks on an AHU | Needed to keep warranties valid |
| Optimal or discretionary | Cleaning schedules, condition surveys | Balances cost against risk and service level |
Standards such as SFG20 classify tasks by criticality so owners can decide what to do and what to let run.
The data chain
- Asset type in the model (for example, "fan coil unit") with a classification code.
- Mapping from the classification to the maintenance standard's schedule (often done in the AIR or by the FM provider).
- Assets (each FCU with tag, location, manufacturer) imported to the CMMS.
- Regime applied to each asset; the CMMS schedules work orders.
- Feedback: work order history builds up against each asset.
Cost planning for maintenance uses the same structure: RICS updated the NRM 3 tables in 2026 to align with SFG20 schedules and CIBSE Guide M life-cycle data.
Worked example
A new office has 420 fan coil units. Handed over as one line "FCUs – various", maintenance would be one vague contract item. Handed over as 420 tagged assets, each mapped to the FCU schedule (filter change quarterly, full service annually), the CMMS generates 1,680 filter tasks a year grouped by floor, and the FM contractor prices them accurately. When five units in one zone fail repeatedly, the history shows it.
Common mistakes
- Handing over assets without the classification needed to assign a regime.
- Treating all assets as equally critical.
- Copying manufacturers' maximum regimes for everything, making maintenance unaffordable, so it's skipped.
- Losing statutory items among hundreds of optional ones.
Where to read more
BESA publishes SFG20. Health and safety and fire safety regulations define statutory inspections in each country. CIBSE Guide M covers maintenance engineering and life expectancy; RICS NRM 3 covers maintenance cost planning.