Lesson 5 of 10 · 10 min
Structuring sites, locations and assets
Written by Melek Mehrez, founder of FreeMaint · Last reviewed October 11, 2026
Lesson objective
By the end of this lesson, you can structure sites, locations and assets into a hierarchy of no more than four levels, write a coding rule and rate each asset's criticality as A, B or C.
Everything in a CMMS depends on the asset hierarchy: work orders, preventive plans, costs and history all point to a location or a piece of equipment. A clear hierarchy makes everything easy to find; a messy one spreads the mess to every report.
This lesson builds that backbone in three decisions: how deep the tree goes, how assets are named and coded, and which assets matter most. Take the time to get them right before importing anything: changing them later means touching every record.
Build the tree: site, area, asset, component
Organize the physical world from the broadest level to the most specific. Three to four levels are enough for most sites: deeper trees look precise on paper and become tedious to navigate on a phone.
| Level | What it is | Example |
|---|---|---|
| Site | A plant, building or campus with its own address | Packaging plant |
| Area | A zone, line or room inside the site | Filling line 1 |
| Asset | A machine or installation that you maintain and track | Filler |
| Component | A part of the asset with its own maintenance, only where useful | Dosing pump |
Locations (site, area) say where things are; assets say what is maintained. Create a component level only when the component has its own preventive tasks, its own failures worth tracking, or moves between machines. Otherwise, describe it in the asset's record.
The ISO 14224 standard, written for the petroleum, petrochemical and natural gas industries but also used in other sectors, describes a similar taxonomy, from the industry and installation down to individual parts. You do not need to follow it to the letter, but it is a good reference when you are unsure about a level.
Name and code assets consistently
A coding rule gives every asset a short, unique identifier that people can read and type. Keep it simple: a few letters for the site, a few for the asset type, and a number.
| Part | Meaning | Example |
|---|---|---|
| PK | Site: packaging plant | PK |
| FIL | Asset type: filler | FIL |
| 001 | Sequence number within the site and type | 001 |
| Full code | Site, type and number, separated by hyphens | PK-FIL-001 |
Write the rule on one page, with the list of site and type abbreviations, and give it to everyone who creates assets. Pair each code with a readable name (“Filler, line 1”) so that requesters who do not know the code can still find the machine.
Rate criticality: A, B or C
Not every asset deserves the same attention. Criticality ranks assets by the consequences of their failure, so that preventive plans, spare parts and the fastest response go first to the assets whose failure hurts most.
Score each asset quickly on four questions: does a failure stop production, does it create a safety or environmental risk, does it affect product quality, and is the repair long and costly? Then sort the assets into three classes.
| Class | Typical consequences of a failure | What it implies |
|---|---|---|
| A — critical | Stops production with no backup, or creates a safety or environmental risk | Preventive plan, critical spares in stock, fastest response |
| B — important | Slows production or affects quality; a workaround exists for a while | Preventive plan where it pays off, planned response |
| C — minor | Little impact, quick and cheap to repair or replace | Simple checks, or run to failure |
As a rule of thumb, class A holds only a minority of assets, often between 10% and 20%. If half the plant is rated critical, the classes no longer help you choose: go back to the questions and compare assets with each other rather than in absolute terms.
Example
The packaging plant's hierarchy
The plant settles on three levels, plus components where they earn their place: the site, eight areas (two filling lines, palletizing, the cold room, utilities, the workshop, the warehouse and the offices) and 40 assets. Only the dosing pumps (two on each filler) become components, because they have their own preventive tasks.
The coding rule fits on half a page: PK for the site, a three-letter type and a three-digit number. The two equipment lists flagged in lesson 3 are merged into a single list of 40 coded assets, each with a readable name.
The criticality review takes one meeting with the maintenance manager, the production supervisor and a field champion: 7 assets are rated A, including both fillers and the compressor, 19 are rated B and 14 are rated C.
Four common mistakes
- A tree six levels deep that nobody can navigate on a phone.
- Codes that include a location or an owner, and change when the machine moves.
- Every asset rated critical, so that the rating no longer helps anyone choose.
- Creating assets one by one before the coding rule is written.
In FreeMaint
Included in Core (free)Locations, assets and criticality in FreeMaint
In FreeMaint, Locations holds your sites and areas, and each asset can have a parent asset to model its components. The Tree view of Assets, with Group by location, shows the whole chain, and the Criticality field offers four levels: Critical (A), High (B), Medium (C) and Low (D). If you work with three classes, use A, B and C. All of this is free on every plan.
Read the documentationTemplate for this lesson
Asset inventory and criticality template
Excel (.xlsx), blank, with formulas
Key takeaways
- Three to four levels are enough: site, area, asset and, only where useful, component.
- Code assets with a short, stable rule and pair each code with a readable name.
- Keep information that changes, such as the current location, out of the code.
- Rate criticality A, B or C from the consequences of a failure, and keep class A small.
Exercise in FreeMaint
Do it in your own FreeMaint workspace, then check it here. Optional: the exercises of lessons 5, 7 and 8 add “with hands-on practice” to your certificate.
Create a location
Create at least one location yourself: a site, a building or an area.
Register three assets
Create at least three real assets yourself. Sample data does not count.
Check your understanding
A few quick questions. Nothing is recorded.