FM Glossary: Facility Management Terms Explained

Updated 25 Sep 2026

In short

This glossary explains 35 common facility management terms in plain English. It covers FM software (CAFM, CMMS, IWMS), maintenance types (PPM, reactive, predictive), performance measures (SLA, MTTR, first-time fix rate), asset data, work management, building technology and FM contract types. Each term has a one-line definition and a short example.

Facility management has a lot of acronyms. Many of them get used loosely, and two teams can mean different things by the same word. This glossary gives a plain definition for each term and a short example of what it looks like in a building.

Where HITEK AI has a longer article on a topic, we link to it.

FM Software and Systems

CAFM (computer-aided facility management)

CAFM is software for running a building’s maintenance and services from one system. It usually covers assets, work orders, planned maintenance, helpdesk requests and reporting.
Example: a tenant reports a leaking tap, the helpdesk logs it in the CAFM system, and a technician gets the job on their phone.

CMMS (computerised maintenance management system)

A CMMS is software focused on maintenance. It tracks assets, work orders and maintenance schedules. The line between CAFM and CMMS is blurry. CMMS tools tend to focus on equipment, while CAFM tools also cover building services and occupants.
Example: a factory uses a CMMS to plan servicing on its production machines.

IWMS (integrated workplace management system)

An IWMS is a wider platform that brings together maintenance, space planning, real estate and lease management, and sometimes project management. Large property portfolios usually buy it for strategic planning, not only day-to-day maintenance.
Example: a corporate real estate team uses an IWMS to track lease dates and desk use across 40 offices.

EAM (enterprise asset management)

EAM software manages physical assets across their whole life, from buying to disposal, often across many sites. It usually links closely with finance and procurement systems.
Example: a utility company uses EAM to track the cost and condition of pumps across its network.

BMS (building management system)

A BMS monitors and controls a building’s equipment, such as HVAC, lighting and pumps. It works at the equipment level, sending set points and reading sensor values. It does not manage maintenance jobs.
Example: the BMS raises a high-temperature alarm on a chiller, and the maintenance team then creates a job to check it.

Maintenance Types

PPM (planned preventive maintenance)

PPM is maintenance done on a fixed schedule to keep equipment working and to catch problems early. Schedules are usually set by time (every three months) or by usage (every 500 running hours).
Example: AHU filters are changed every quarter whether they look dirty or not.

Reactive maintenance

Reactive maintenance is work done after something breaks or someone reports a fault. Some of it is unavoidable. Too much of it usually means planned maintenance isn’t catching problems early enough.
Example: a lift stops between floors and an engineer is called out.

Predictive maintenance

Predictive maintenance uses data from equipment, such as vibration, temperature or run hours, to spot early signs of failure. The work is done when the data shows it’s needed, before the equipment fails.
Example: rising vibration on a pump motor points to a worn bearing, so the bearing is replaced during a quiet period.

Condition-based maintenance

Condition-based maintenance is done when a measured condition crosses a set limit. It’s close to predictive maintenance. The difference is that it reacts to a threshold rather than forecasting a failure.
Example: a filter is changed when the pressure drop across it passes a set value.

Corrective maintenance

Corrective maintenance fixes a fault that has been found. The fault might come from a breakdown, an inspection or a PPM visit. People sometimes use it to mean reactive maintenance, but corrective work can also be planned.
Example: during a PPM visit, a technician finds a cracked fan belt and books a follow-up job to replace it.

Planned vs reactive ratio

This ratio compares how much maintenance work was planned with how much was reactive. It’s usually measured in work orders or labour hours. Teams track it to see whether they are getting ahead of breakdowns.
Example: out of 200 jobs last month, 150 were planned and 50 were reactive.

Performance Measures

SLA (service level agreement)

An SLA is the agreed standard for a service, written into a contract. In FM it usually sets response and completion times for each type of job.
Example: an emergency job must be attended within 1 hour, and a routine job within 24 hours.

KPI (key performance indicator)

A KPI is a measure used to judge how well a service is performing. FM contracts often link KPIs to payment or penalties.
Example: the percentage of PPM jobs completed on time each month.

MTBF (mean time between failures)

MTBF is the average running time between one failure of an asset and the next. A higher MTBF means the asset fails less often.
Example: a pump that ran 3,000 hours and failed 3 times has an MTBF of 1,000 hours.

MTTR (mean time to repair)

MTTR is the average time it takes to fix an asset after it fails, from the start of the repair until it works again. A lower MTTR means faster repairs. Some teams measure from when the fault is reported, so check which definition a contract uses.
Example: three repairs took 2, 3 and 4 hours, so the MTTR is 3 hours.

First-time fix rate

This is the percentage of jobs finished on the first visit, with no return trip. Missing parts, wrong skills and poor fault descriptions are common reasons for a second visit.
Example: 85 of 100 jobs were closed on the first visit, so the first-time fix rate is 85%.

Asset uptime

Asset uptime is the share of time an asset is available to work when it’s needed. Some teams call it availability.
Example: a chiller needed for 720 hours in a month was down for 7.2 of them, so its uptime was 99%.

Assets and Data

Asset register

An asset register is the master list of equipment a team maintains. Each asset usually has an ID, location, make, model, install date and maintenance history. Most FM software depends on this list being accurate.
Example: the register lists every fan coil unit in a tower, with its floor and room.

Asset hierarchy

An asset hierarchy groups assets into parent and child levels, such as system, equipment and component. It makes reporting clearer and helps technicians find the right item.
Example: HVAC system > chiller 1 > compressor.

Asset tagging

Asset tagging is fixing a label to each asset, usually a QR code, barcode or RFID tag, that links it to its record in the system. Technicians scan the tag to open the asset’s details and history.
Example: a technician scans the QR code on a pump to see its last three jobs.

Asset lifecycle

The asset lifecycle covers every stage of an asset’s life: planning, buying, installing, running, maintaining and finally replacing or disposing of it. Lifecycle data helps teams decide when repairing stops making sense.
Example: repair costs on an old split AC unit now exceed the cost of a new one, so it’s scheduled for replacement.

Location hierarchy

A location hierarchy is the structure of places in a portfolio, such as site, building, floor and room. Assets and jobs are linked to locations so teams know exactly where work is.
Example: Site A > Tower 2 > Level 14 > Pantry.

Work Management

Work order

A work order is a record of a maintenance job. It says what needs doing, where, by whom and by when. It also records what was done, the time spent and the parts used.
Example: “Replace light fitting, Level 3 corridor, due today, assigned to electrician.”

Helpdesk

The helpdesk is the team or system that receives requests and fault reports from building users and turns them into jobs. Requests may come in by phone, email, app, portal or chat.
Example: an occupant reports a warm meeting room, and the helpdesk raises a job for the HVAC technician.

Service request

A service request is a request from a building user. It can be a fault report or a request for a service, such as moving furniture or extra cleaning. Not every service request becomes a maintenance work order.
Example: a tenant asks for a room to be set up for a training session.

Job card

A job card is the document or screen a technician uses to carry out and record a job. In many teams, and often in the Gulf, it means the same as a work order.
Example: the technician closes the job card on their phone with a photo of the finished repair.

Permit to work

A permit to work is a formal written approval for high-risk work. It sets out the hazards, the controls and who is authorised to carry out the job. It’s common for hot work, confined spaces and electrical isolation.
Example: before welding in a plant room, the contractor gets a hot work permit signed off.

Building Technology

FDD (fault detection and diagnostics)

FDD software checks building equipment data against expected behaviour, flags faults and suggests likely causes. It can find problems that don’t trigger a standard alarm.
Example: FDD spots an AHU heating and cooling at the same time, which wastes energy without setting off any alarm.

Anomaly detection

Anomaly detection finds readings that break an asset’s normal pattern. It learns what “normal” looks like from past data, so there’s no need to set a fixed limit for every value.
Example: a pump’s power draw creeps up over two weeks, and the system flags it before it fails.

IoT sensor

An IoT sensor is a connected device that measures something, such as temperature, humidity, vibration, occupancy or water leaks, and sends the data over a network. FM teams use them to monitor places and equipment that a BMS doesn’t cover.
Example: a leak sensor under a server room floor sends an alert as soon as it detects water.

Smart meter

A smart meter measures electricity, water or gas use and sends readings automatically, often every few minutes. The data shows where and when energy is used.
Example: smart meter data shows a building using power overnight when it should be empty.

FM Contract Types

Hard FM

Hard FM covers services linked to the building’s physical structure and systems, such as HVAC, electrical, plumbing, lifts and fire systems. These services are usually needed for safety and compliance.
Example: quarterly servicing of fire alarm panels.

Soft FM

Soft FM covers services for the people who use a building, such as cleaning, security, landscaping, pest control and reception.
Example: daily cleaning of offices and washrooms.

TFM (total facility management)

Under TFM, one provider delivers all hard and soft FM services for a site under a single contract. The client deals with one supplier.
Example: one company handles maintenance, cleaning and security for a mall.

IFM (integrated facility management)

IFM means managing several FM services together under one management structure, with shared reporting. People often use it to mean the same as TFM. In some contracts, though, the IFM provider manages specialist subcontractors instead of doing all the work itself. Check how a contract defines it.
Example: an IFM provider runs the helpdesk and reporting while specialist firms handle lifts and fire systems.

Read more in detail: TFM vs IFM: What is the difference?