What is the Definition of Downtime in Lean Manufacturing?

Calendar icon

By Emilie A Lachance - July 08, 2019

What is Downtime?

Words are important, they help us to come to a common understanding. Sometimes in high stress environments like the modern manufacturing floor, we can have a tendency to talk past one another and this isn't productive. At Worximity, our technology facilitates a shared understanding of the actual state of our manufacturing KPIs, but sometimes we find that our customers don't have a shared agreement on what specific, commonly used terms actually mean. Today we're going to discuss downtime, and specifically, what 'Downtime' means in manufacturing.


Downtime is the period of time in which a system or machine is out of order. In the manufacturing industry, it refers to the period of time in which a company’s factory is not producing product. This can hurt a company’s bottom line and profit margins, as often downtime is unplanned and occurs while normal business functions continue, including paying employees and ordering material to manufacture products. 

Downtime is costly and not uncommon, as a ServiceMax sponsored study found that 82% of companies surveyed had experienced at least one unplanned downtime event in the previous three years, with the average number of outages being two. These outages lasted an average of four hours and cost the companies an average of $2 million. Aberdeen research also found that unplanned downtime cost companies an average of $260k for every hour of downtime, while a 2006 study by Advanced Technology Services, Inc. found that car manufacturers lost $22k for every minute of downtime.

Examples of Downtime

There are many different events or issues that can cause downtime, both planned and unplanned, but the downtime that does the most damage to a company is unplanned. Planned downtime is usually some sort of scheduled maintenance or simply a time when a machine or system isn’t operating because it is unneeded at the time. Unplanned downtime is usually when an unexpected problem has occurred somewhere in production.

The following are some examples of downtime:

Hardware failure

  • Hardware failure is fairly self-explanatory, as it is when part of a machine breaks or malfunctions, halting all use of the machine for production tasks.

Waiting on materials

  • Materials are necessary for most types of manufacturing and production, so when a system is starved, meaning it does not have enough material to make a product, downtime will occur. 

Excessive changeover time

  • Changeover refers to when a machine or production line is being converted from producing one product to another. This can often be considered planned downtime, but if the conversion process takes longer than expected or delays occur during the process, it is considered unexpected downtime. 

Lack of operator

  • A missing operator can be considered planned or unplanned downtime depending on the circumstances. If an operator or operators are not scheduled to be at work a certain time, this can be considered planned downtime, as the company knows that these employees will not be present to operate the system or machines. If an operator is not present but the absence was unexpected, this is of course an example of unplanned downtime.

Machine maintenance

  • Scheduled machine maintenance is considered planned downtime, but unscheduled maintenance, as a result of hardware failure or attempting to avoid it is considered unplanned downtime.

With a clear understanding of downtime, you're now prepared to organize your team around the next step, measuring it and reducing it!

Beyond measuring, quantifying and reducing downtime, there are lots of great business reasons to get onboard with automatic factory data collection.

Learn more in our guide here:

7 Reasons You Need to Switch to Automatic Real-Time Data Collection eBook

The Worximity Smart Food Factory solution is a low-cost hardware system that can be up and running in a few hours combined with an easy and intuitive yet powerful analytics dashboard that provides fast ROI to start and a roadmap to full-on IIoT success.

Subscribe to our newsletter

Are you a best-in-class OEE Performer? Worximity OEE Ebook