CMMS vs CAFM vs BMS, explained

The one-line answer

BMS controls equipment. CMMS manages maintenance work on that equipment. CAFM manages the whole facility, including space and services, and usually includes maintenance as one module.

The confusion comes from vendors stretching each label. A BMS vendor adds a “maintenance” screen, a CMMS vendor adds a floor plan, a CAFM vendor calls itself “building management”. Ignore the labels and ask what problem each tool solves.

What each one does

BMS: building management system

A BMS is a control system. It reads sensors and runs plant through controllers: chillers, AHUs, pumps, car park fans, lighting schedules. Its users are engineers, and its main outputs are setpoints, schedules, trends and alarms. It does not know who your technicians are. For more detail, see what a building management system is.

CMMS: computerised maintenance management system

A CMMS is a work system for maintenance. Its core objects are assets and work orders. It holds the asset register, schedules preventive maintenance, takes reactive requests, assigns jobs to technicians, records labour and parts, and keeps a history per asset. Its users are maintenance managers, chief engineers and technicians.

CAFM: computer-aided facility management

CAFM grew out of space planning: floor plans, room data, occupancy and moves. Modern CAFM tools usually add a helpdesk, maintenance (CMMS-like), room and desk booking, visitor management and soft services such as cleaning and security. Its users include facility managers, workplace teams and service providers. Facility management as a discipline is described in the ISO 41001 management system standard, and CAFM tools are designed to support that broader scope.

Side-by-side comparison

Where they overlap, and where they do not

The real overlap is between CMMS and CAFM. Both handle work orders and planned maintenance. The difference is scope: a CMMS goes deep on assets and maintenance, a CAFM goes broad across space and services.

The BMS overlaps with neither in any serious way. It is the source of many maintenance signals, such as alarms, run hours and filter pressure, but it does not manage the response. Where integrations exist, the useful pattern is one-directional: a BMS alarm creates a work order in the CMMS or CAFM, and the technician closes it there.

What all three often miss

Frontline coordination is where many buildings still struggle, whatever software they own. Requests arrive by phone, email, WhatsApp and the front desk. Housekeeping, security, concierge and maintenance all need tasks assigned and tracked, not just engineers. Some CMMS tools are designed around a planner at a desk, and the technician’s mobile experience is an afterthought. If your problem is “work gets lost between people”, check how each candidate handles intake, assignment, escalation and proof from the technician’s phone, not just the asset register.

One fault, three systems: a worked example

The easiest way to see the difference is to follow a single fault through a building that has all three.

At 6:40 on a Monday morning, the supply fan on AHU-3, which serves the fourth-floor offices, trips on overload. The BMS sees the fan status drop while the start command is still on, and raises a “fan fail” alarm on the front end. It may also try a restart, depending on how it was programmed. That is the end of the BMS’s job: it has detected the fault and told someone.

The duty technician sees the alarm and raises a work order in the CMMS: asset AHU-3, fault “supply fan trip”, priority high because the floor will be occupied by 8:30. The CMMS shows the asset history: the same fan tripped twice last quarter, and its belt was replaced six weeks ago. The technician finds a seized bearing, replaces it, records the part used and the time spent, attaches a photo and closes the job. The chief engineer adds a note to bring the AHU’s annual bearing check forward.

Meanwhile, tenants on the fourth floor notice the stuffy air. In a building with a CAFM helpdesk, their complaints arrive as service requests linked to the fourth-floor space. The facility manager sees that two meeting rooms on that floor are booked for a client workshop and moves the bookings to the sixth floor until the repair is done. At month end, the CAFM report to the owner shows comfort complaints by floor alongside occupancy.

Three systems, three different jobs. Remove the BMS and nobody knows about the fault until tenants complain. Remove the CMMS and the repair happens but nobody records the repeat failure. Remove the CAFM and the workshop goes ahead in a hot room. In a residential tower, the CAFM part of this story mostly does not exist, which is why a CMMS or operations platform is usually enough there.

How to choose

Start with your building type and your actual pain.

• Single residential tower or a small portfolio of residential buildings. You need a BMS if you have central plant. For work, a CMMS or operations platform that handles resident requests, preventive maintenance and contractor jobs is usually enough. Space management is not a priority.
• Commercial office building. BMS for plant. CMMS for maintenance. Consider CAFM if tenants book rooms, you manage fit-outs and moves, or you report occupancy to the owner.
• Facility management company running many client sites. You need strong work management across sites and clients, with reporting per contract. CMMS or CAFM, depending on whether your contracts include space and soft services.
• Hotel or serviced apartments. The PMS runs reservations and billing. Engineering may have a BMS. For housekeeping, maintenance and guest requests across departments, you need an operations tool that the whole team uses, not only engineering.

Questions to ask in a demo

• Show me a request going from report to assigned technician to closed, on the technician’s phone.
• What happens when a job is late? Who gets told, and when?
• How is proof of completion recorded?
• How do I schedule preventive maintenance and see what is overdue?
• What reports can I show the owner each month?
• For a BMS link: which alarms create work, and who maintains that mapping?
• What will my team stop doing on day one? If the answer is “nothing”, adoption will be slow.

Common buying mistakes

• Buying the biggest suite for a small problem. A full CAFM bought to fix lost maintenance requests often ends up used only for its helpdesk.
• Ignoring the people who will use it most. Technicians and housekeepers use the system every hour. If their app is slow or confusing, the data will be wrong.
• Assuming the BMS covers maintenance. It tells you that something is wrong. It does not make sure it gets fixed.
• Paying for an integration before the process works. Get alarms turned into work orders by hand first. Automate once you know which alarms matter.

Where TaskLoop fits

TaskLoop is an operations platform rather than a BMS or a space-planning CAFM. It covers the shared work layer across buildings, hotels and frontline teams: requests are registered and assigned in an admin dashboard with priority, deadline and instructions, staff complete them in a mobile app with status updates and optional photo proof, overdue tasks escalate to supervisors, and reports show response and completion times by team. For the building side, see building management software and work orders.

Summary

The BMS runs the plant. The CMMS runs the maintenance. The CAFM runs the facility. Buy for the problem you have, check how work actually moves between people, and do not expect any one label to cover everything.