Guides · 20 September 2026

CMMS vs field service management software

One is organised around the machine. The other is organised around the job and the customer. Almost everything else follows from that.

Put a CMMS and a field service management system side by side in a demo and they look like the same product. Both have a list of work. Both have engineers you assign it to. Both have a mobile app and a photo upload and a signature box. An hour in, the honest question is what you are actually choosing between.

The difference is not the feature list. It is what each one is organised around — and that decides what it is good at, what it quietly loses, and which of your problems it will not solve no matter how many modules you buy.

The one-sentence version

A CMMS is organised around the asset. Its central record is a machine, and work is something that happens to that machine. (A fuller definition here.)

Field service management is organised around the job and the customer. Its central record is a visit someone is dispatched to, and the machine is a detail on it.

Both are legitimate ways to run a business. They just answer different questions, and the question you cannot answer today is the one that should decide it.

The test: what happens when the work is finished

This is the sharpest practical difference, and it is worth asking in any demo.

In a field service system, finishing a job closes it. The customer gets a report, the office gets something to invoice, and the job moves to a completed list. The work is now a transaction in a history of transactions, filed by date and by customer.

In a CMMS, finishing the work writes to the machine. The visit, the parts changed, the readings taken and the notes left all land on the asset record, where the next person to stand in front of that unit will find them — in eighteen months, in a different van, having never seen it before.

What each one holds that the other usually does not

On the CMMS side, the things field service tools tend to lack:

  • An asset register that is the spine of the system rather than a dropdown on a job form.
  • Parts fitted per machine, and a history of what was changed and when — not just what was invoiced.
  • Manuals, wiring diagrams and bulletins attached to the equipment rather than filed by supplier.
  • Preventive maintenance schedules, meter readings and condition data, where the work is planned rather than reactive.

On the field service side, the things a CMMS often has no answer for:

  • Scheduling and dispatch — a board of who is where, and routing between sites.
  • Customers as first-class records, with the contract, the rates and the site contacts.
  • Quoting and estimating before the work is agreed.
  • Invoicing what was done, and the paperwork the customer signs on the day.
  • Van stock and what the engineer is carrying.

Neither list is universal. Products cross the line in both directions, and plenty of them have bolted on the other half badly. Reading the lists is less useful than asking which half the product was originally built for, because that is the half that will be coherent.

Which one you need

Four questions that usually settle it faster than a feature matrix:

  • Do you own the equipment, or does your customer? In-house maintenance teams maintain their own plant and almost always want a CMMS. Contractors maintaining other people's kit have customers to bill and usually reach for field service software first.
  • Is the work planned or does it arrive by phone? Planned work rewards scheduling and PM calendars. Reactive work rewards knowing the machine before you get there.
  • Who asks the awkward question? If it is a finance director asking what this contract cost to service, that is field service. If it is an engineer asking what happened to this chiller last winter, that is a CMMS.
  • What breaks when someone leaves? If the answer is the schedule, you need dispatch. If the answer is the knowledge, you need an asset record.

Why a lot of firms end up needing both

A maintenance contractor is the awkward case, and it is a common one. They are commercially a field service business — customers, jobs, signed sheets, invoices — and operationally a maintenance business, because the thing that makes an engineer effective on a call-out is knowing what was done to that machine the last three times.

The usual outcome is two systems and a person in the middle. The field service tool holds the jobs and the money; the machine history lives in a spreadsheet, a shared drive, or one engineer's head. It works until the spreadsheet is a year out of date, which it will be, because nobody is paid to update it after a fourteen-hour day.

The way out is not a bigger system. It is making the history a by-product of doing the work rather than a second job afterwards — so closing the job on site is what writes the machine's record, and there is nothing left to transcribe.

Where Repair Control sits

Deliberately across the line, with the two spines joined. Jobs are dispatched to engineers against a customer, closed from the field, turned into a work order the customer signs, and billed — and closing that job is also what writes the visit, the parts changed and the time clocked onto the machine's own record. One action, both halves.

What it does not have, on each side, because the worst way to learn this is three weeks into a trial:

  • No scheduling or dispatch board. Jobs carry a due date and an assigned engineer. There is no calendar view, no drag-and-drop day, and no routing between sites.
  • No preventive maintenance. Nothing recurs on its own, and there are no meter readings or condition triggers.
  • No quoting, no stock, no van inventory. Work is invoiced after it is done, from the jobs themselves.

So: a good fit for a contractor whose work arrives by phone and whose real problem is that nobody remembers what happened to the machine last time. A poor fit if what you need first is a schedule for planned work across a fleet you own. What it costs.

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