What is a CMMS, and why start it from the machine?

A CMMS (computerized maintenance management system) is the software where a plant requests, plans, records and reviews maintenance work. For a production plant it does four jobs: it turns machine problems into work orders, brings preventive tasks due, tracks spare parts and keeps each machine's repair history. It fits the floor when work orders start from what the machines report, with the stop time attached, instead of from somebody remembering to file one.

This guide is for maintenance leads and plant managers choosing a CMMS or fixing one nobody uses. It covers what the system holds, where work orders should come from, why hand-entered history misleads, and how to judge fit.

What is a CMMS?#

The US Department of Energy’s operations and maintenance guide describes a CMMS as management software that supports managing and tracking maintenance activities. It adds that a CMMS makes no decisions: it gives the maintenance manager the information to make them.^[1]

Under every screen, a CMMS holds four records.

Everything else is a view of those four. The backlog is a filtered list of open work orders. A machine’s history is every closed work order that names it. A reorder list is the parts whose stock fell below their reorder point.

CMMS, MES and machine monitoring#

Plants often confuse three systems that answer different questions.

They meet at one point: a machine stop is a monitoring event, and the repair it needs is a CMMS work order. The side-by-side, with where each sits in ISA-95, is in machine monitoring vs MES vs CMMS.

What a CMMS does for a production plant#

The DOE guide lists the functions a CMMS covers, depending on the system.^[1] Here they are with a plant example for each.

Choosing which PM goes on a date and which on run hours is its own decision, covered in how to choose a maintenance strategy.

A large share of that work doesn’t start as a plan. In NIST’s survey of US manufacturers, an average of 45.7% of machinery maintenance was reactive.^[3] Each of those jobs starts with a failure that has to reach the CMMS, so where work orders come from decides whether the CMMS is current.

The DOE guide frames the need as a set of questions.^[1] Consider a CMMS when you can’t answer these from records:

• When was this machine last serviced, by whom, and what did they find?
• Which work is open right now, and who has it?
• Are you waiting on parts, or carrying stock nobody uses?
• Where are the manual and the lockout procedure for this machine?

You don’t need one yet if one technician does every job on a handful of machines and keeps a log current. Move when a second person needs the same history, or when PM tasks start slipping.

Where work orders come from#

A CMMS is only as current as its work orders. A work order can start in six ways, and each one fits a different kind of work.

Pick the origin by who knows first. The machine knows first about a stop, a shock or its run hours. An operator knows first about a leak or a smell. A planner knows first about a rebuild.

The DOE guide gives the machine-first pattern for an air filter. A pressure sensor reports when the filter needs changing, the CMMS opens the work order on that need instead of every three months, and the filter comes out of stock with a reorder if needed.^[1] The same logic works for a spindle, a die or a mold.

The difference shows most on a night shift. On paper, a tool crash at 22:12 becomes a work order the next morning, with a start time somebody guesses. From the machine, the stop is on record to the second and the work order carries it.

RNPSA, a mining equipment manufacturer in Matehuala, Mexico, describes its old path the same way: an operator told the shift supervisor, who wrote a note, which the next shift supervisor read before calling maintenance. Now the operator who classifies a stop opens the work order in the same step, and RNPSA halved its maintenance response time.

Continuous vibration monitoring gave us eyes we never had before. We can see tool crashes that would have been invisible, identify the exact moment and severity, and pull historical data to understand what went wrong. Add in Maintain, and suddenly operations and maintenance aren't working in silos, we're collaborating on the same data in real-time. That's transformed how we manage these critical machines.

Why hand-entered maintenance history misleads#

A CMMS computes response time, repair time and backlog age from timestamps. When people type those timestamps after the fact, every report built on them inherits the error.

NIST researchers studied ten years (2009 to 2019) of HVAC work orders from a mixed laboratory and office site. Work orders opened across the whole working week, between 13% and 24% on each weekday. Yet 19,597 of 21,107, about 93%, were closed on a Friday.^[2]

The closings fell on only 520 days in ten years, about one close-out a week. The authors conclude that the closing dates almost certainly don’t match when the work finished, so durations computed from them can’t be trusted.^[2] The dataset also lacked the timestamps needed for time to dispatch, one of the measures the authors ranked most important.^[2]

The site was a building, not a production line, but the cause transfers. The authors note that maintenance staff type work orders by hand, often under time pressure, into systems that fit their needs poorly.^[2] Here is what a Friday batch does to mean repair time on a hypothetical CNC cell.

Take the start of a breakdown from the machine’s stop and its end from when the machine ran again. Then a late close-out changes the paperwork, not the repair time. That needs stop reasons that tell a breakdown from a changeover, which is what downtime reason codes are for.

What makes a CMMS fit the floor#

A CMMS fits the floor when the people and machines closest to a problem can put it on record in seconds. Check these in a trial, on your own machines.

The last row matters more than it looks. Per-user pricing pushes plants to ration logins, and an operator with no login files no requests. The problem then travels by word of mouth, as on the paper path above.

The DOE guide names the common ways a CMMS fails: the wrong system for the site, too little training for the staff who enter data, and no commitment to implement it and keep using it. It adds that feature overload is a common complaint, and that most successful installations have a champion who keeps people using it.^[1]

Choose a standalone CMMS when most of your work is facilities and building upkeep, or when your machines already report stops into a system you will connect. Choose a CMMS built on machine monitoring when breakdowns and wear on production machines drive most of the work, because the stop, the run hours and the part count are already recorded.

Start maintenance from the machine with IoTFlows#

IoTFlows Maintain is a CMMS built on machine monitoring. A work order is its only object: a request, a planned job and a preventive schedule are the same record with different fields filled in.

Work orders open from five places: by hand, from a classified stop, from a machine event rule on health, shock or temperature, from a meter, or from an operator’s request in the job runner or on a phone. A meter counts runtime hours or parts, emails at 85% and opens the work order at 100%.

A work order holds the parts it needs in Inventory, and marking it Done moves the stock. As of October 2026, Maintain starts at $500 a month with unlimited users, on top of machine monitoring. Device plans are on the pricing page.

Roll out a CMMS your floor will use#

1. Load the machines that matter first

   Rank machines by what an hour of downtime costs, using how to calculate the cost of downtime. Enter the top 10 with their manuals, lockout procedures and critical spares.

2. Agree which stop reasons mean maintenance

   Mark the reasons that need a technician, such as tool crash, hydraulic leak and spindle fault, apart from changeovers and material waits.

3. Give every operator a way to request work

   Put the request one step from the machine: on the operator screen, the job screen or a phone. Ask for a photo instead of a long description.

4. Move recurring tasks in, and meter the wear items

   Enter each calendar PM as a recurrence. Move tasks on parts that wear with use to run hours or part counts, as in usage-based maintenance.

5. Turn on machine-opened work orders one type at a time

   Start with shock events on CNC machines or health alerts on your most critical motor. Add the next type once the team triages the first within a shift.

6. Read the history every month

   Count closings by weekday. If most work orders close on one day, your durations are batch close-outs, and repair times should come from the machine’s stops instead.