There are different ways to examine workflows, policies, and practices to find and fix inefficiencies. But just like all tools, some are better than others. Wrench time, for example, is a maintenance metric that tends to make less sense the more closely you look at it. 

So, what is a wrench time study, and should you invest in one? 

Before looking at how to study something, it’s important to first understand what it is, and especially with wrench time, also what it’s not. 

What is wrench time? 

Wrench time is the time maintenance technicians spend actively working on inspections and tasks. It’s when they’re holding tools, working on your assets and equipment. 

It’s also important to understand it through the negative. Wrench time is not when techs are collecting work orders and reading through them to understand their next inspections or tasks. It’s also not when they’re collecting the tools, parts, and materials they need to close out their assigned work orders. Wrench time does not include tech travel time to and from assets, and it does not include any breaks techs might take. 

Generally, and there are differences across industries, the average maintenance tech’s day is only about 30% wrench time. Outside of that small window, they’re not actively working on assets and equipment. 

Why is wrench time important? 

By adding one more element to the definition, you can quickly see the perceived importance. Wrench time shows what percentage of the day techs are doing exactly what you want to be paying them for, working directly on assets and equipment. When you go to a restaurant, you want to pay for the kitchen to prepare and cook the food. But you would rather not pay for the time it takes the chef to run to the store to shop before they start cooking. And you don’t want to pay for the time it takes them to wash all the dishes after you’ve left. It’s the same when you think about paying techs. 

So, in theory, if you can accurately track and then consistently boost wrench time, you get more work out of your maintenance technicians for the same amount of money. Instead of paying them to be onsite for eight hours but only on the assets for three, you could get extra hours of direct maintenance for the same costs. 

But in practice, there’s a number of reasons why this is likely impossible. 

Why is wrench time not important? 

There’s a good chance wrench time is a misguided maintenance metric because it leaves out many of the activities that are both essential and value-adding to maintenance. So, although it doesn’t include the time it takes to properly prepare to work, techs do need this time. In fact, you likely want to encourage techs to take the time to make sure they have the right parts and materials, have read work orders carefully, and if halfway through a task they need to take a step back and do some careful thinking, that’s exactly what you would want them to do. 

On top of risking incentivizing the wrong types of behaviors, tracking wrench time might also be telling you the wrong things about your maintenance operations. High wrench time rates could mean everything is going well and you’ve streamlined workflows so techs can concentrate on getting their hands on the assets. But it’s also just as possible that high wrench time numbers mean techs are working more slowly than they should be. 

For example, if a job that should take one hour suddenly takes three because of a lack of training, your wrench time still goes up. You’re getting slower, worse work, but your metric tells you things are getting better. 

How can you measure wrench time and what is a wrench time study? 

Putting aside the possibility that wrench time is a misguided maintenance metric, if you want to track it, you have to make sure you’re doing it correctly. 

Here are some of the more common ways to measure it, ranked from acceptable to best practices. 


One way to track how long work takes is to just ask the technicians to track their time. Although this method is sometimes the easiest, it can be the least reliable. Tech might not have a clear understanding of what wrench time is, and if they do, they might be tempted to exaggerate their numbers. 


A more objective method is to have someone follow techs around, recording their “day in life of” time on wrench. But, on top of being more objective, with this method, you often run the risk of being more objectionable. People don’t like being followed around and watched.   


You can also have someone come out and check on the maintenance techs at set intervals. Each sample then includes information about who was working directly on maintenance. Over a certain amount of time, you collect enough data for overall averages. The issue here is you need a way to check on all the techs at the same time, which is challenging unless everyone is working in the same area of a single site. 


Statistic-based studies can help you get accurate numbers without worrying about upsetting techs or having to develop elaborate monitoring systems. 

Here, you set up intervals to randomly check on different techs, each time checking to see if they’re on wrench or not. The trick is setting up enough intervals over a long enough time to counteract the effects of any outliers. 

Although there are ways to conduct a wrench study, it’s important to remember there are also reasons to avoid them. In some cases, techs might be unhappy about the studies, and that means you’re not only losing goodwill, you’re also not getting good data. Another reason to avoid them is that there are other, better metrics you can use to get more accurate information about your operations. 

Consider the assumed goal of a wrench study: finding inefficiencies in how you manage work orders, parts, and planning. If wrench time is low, it means that techs are wasting time on getting ready to work when they could be actually working. But if you’re looking for inefficiencies, all you need to do is check things like close-out rates, how much you’re spending on rush deliveries on parts, and the ratio of on-demand to preventive maintenance. There’s a long list of easier, better maintenance metrics and key performance indicators (KPIs) you can track. 

How can an EAM help increase wrench time? 

That said, increasing wrench time can still be a solid goal, and you can likely achieve it without having to measure or focus on it specifically. By streamlining your workflows and improving inventory control, techs can focus their time and attention on working directly on assets and equipment. The right enterprise asset maintenance (EAM) solution can help. 

Modern EAM systems help you take control of work order management and inventory control. Instead of trying to stay organized with paper or spreadsheets, and EAM has all your data in one central location, where it is safe, secure, and accessible to the entire maintenance team, from anywhere. Because techs don’t have to waste time running back and forth to the office to grab paperwork, they can spend more time focused on maintenance. 

The maintenance management software also helps you track inventory, ensuring you have accurate counts, so you never find yourself out of stock on critical parts. You can also leverage all the historical work order data in the system to better predict future needs, helping you set par levels. More data, and more accurate data, means you have better insights into all sides of your operations. 

Next steps

To find out how EAM software can support your goals, schedule a demo of ManagerPlus Lightning today. 

CEO summary 

Although wrench time is a longstanding maintenance metric, there are likely more effective ways to find and fix inefficiencies in the maintenance department. That said, it is important to understand wrench time and how wrench time studies can work before making a final decision. Wrench time is the time technicians are actively working on assets and equipment, and it excludes all the time spent on preparation, including collecting parts and materials, reading work orders, and traveling to the assets and equipment. On average, time on wrench is only about 30% of techs’ day. You can conduct a wrench time study by following techs around to see how much time they spend on direct maintenance work. However, there are important limitations. One is that wrench time itself is not always a good indicator of the techs’ efficiency. So, they might be spending a lot of time working on assets, but it might be too much time considering the tasks, in which case high wrench times might simply be because of a lack of training. In the end, there are so many other KPIs you can use to track and improve your operations. For all these maintenance metrics and KPIs, though, a modern EAM solution can help you capture reliable data and then leverage it into actionable business intelligence. 

About the author

Jonathan Davis

Jonathan has been covering asset management, maintenance software, and SaaS solutions since joining Hippo CMMS. Prior to that, he wrote for textbooks and video games.
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