--- title: What is machine downtime, and what does it really cost? url: https://www.opero.pro/resources/what-is-machine-downtime collection: resources --- **Kind:** guide · **Read time:** 6 min · **Author:** Opero · **Tag:** Glossary · **Published:** 2026-10-06 ## TL;DR - **Definition** — machine downtime is any period when a machine should be producing and is not. - **Two kinds** — planned (maintenance, changeovers) and unplanned (breakdowns, missing parts, waiting for the one person who knows the fix). - **The cost** — lost output per hour, plus labour standing idle, plus late deliveries. Most plants count the first and forget the other two. ## What machine downtime means Machine downtime is the time a machine is not running when the production plan says it should be. A press that is being repaired is down. A packaging line that waits for a technician is down. A CNC machine that stands still because the operator is looking for the manual is also down, even though nothing is broken. The word covers both the short stops that happen ten times a day and the long breakdown that takes a shift to repair. Both count. The short ones are often the bigger total. ## Planned and unplanned downtime Planned downtime is time you decided to stop. Preventive maintenance, changeovers between products, cleaning, software updates. You can schedule it when it hurts least, and you can shorten it with good procedures. Unplanned downtime is time the machine took from you. A bearing fails. A sensor gives a false alarm. A fault code appears that nobody on the night shift has seen before. This is the kind that costs the most, because nobody was ready for it. A useful rule: planned downtime is a cost you manage, unplanned downtime is a cost you discover. ## How to measure it Keep it simple. For each machine, record three things per stop: - When it stopped and when it ran again - Why it stopped, in one line - Who fixed it and what they did From that you get total downtime per machine, per shift and per cause. Most CMMS systems record the first two if people fill them in. The third one, what was actually done, is the part that is usually missing, and it is the part that saves time the next time the same fault appears. If you use OEE (overall equipment effectiveness), downtime is the availability part of the formula. Availability is run time divided by planned production time. A line planned for 8 hours that ran 6.5 hours has an availability of 81 percent. ## What an hour of downtime costs Add three numbers: 1. **Lost output.** Units per hour multiplied by the margin per unit. If the line makes 400 units an hour and you earn 5 euros on each, one hour costs 2,000 euros in margin alone. 2. **Idle labour.** The operators and technicians who are paid while the machine stands still. 3. **Knock-on cost.** Overtime to catch up, late deliveries, penalties, scrap from a bad restart. Most plants know the first number. Few add the second and third. When you add them, an hour of unplanned downtime on a main line is often two to three times what people assumed. ## The four causes behind most unplanned downtime In the plants we work with, four causes come up again and again: **1. The fault is known, but not by the person on shift.** The machine stopped with the same fault last year. Someone fixed it in twenty minutes. That person is on holiday, and nobody wrote down what they did. The fix takes three hours this time. **2. The information exists but is scattered.** The manual is in SharePoint, the maintenance history is in the CMMS, the supplier's workaround is in an email from 2023. Finding all three takes longer than the repair. **3. Waiting for a part.** The technician finds the fault quickly, then spends an hour working out the right part number and whether it is in stock. **4. Reports are not written, so the pattern is never seen.** When a stop is not recorded properly, nobody notices that the same machine has stopped for the same reason six times this quarter. Only the third cause is about logistics. The other three are about knowledge: having it, finding it and keeping it. ## How to reduce machine downtime Start with the repeat faults. Pull the stops from the last six months, group them by machine and cause, and look at the top five. They are usually a large share of the total, and each one already has a known fix somewhere in the company. Then make the fix easy to find at the machine. A technician on the night shift should be able to ask "line 3 stops with fault E-12, what do I do?" and get the steps, with the manual page or the previous repair next to them. That is the problem Opero was built for. Technicians ask by chat, voice or video, and the answer comes from your own manuals, CMMS history and recorded repairs. Finally, record what was done, every time. The fastest way is a short video of the repair. The technician films the fix, and Opero turns it into a written report that goes into the CMMS and into the knowledge base. The next person who meets the fault finds it in seconds. ## Related terms - **MTTR, mean time to repair.** The average time from stop to restart. Knowledge problems make this number long. - **MTBF, mean time between failures.** The average running time between two stops. Preventive maintenance improves this number. - **OEE, overall equipment effectiveness.** Availability multiplied by performance multiplied by quality. Downtime lowers availability. - **Preventive maintenance.** Scheduled work done to stop a failure before it happens. If you want to see how this works on one of your own machines, [book a 20-minute demo](/contact).