5 Things You Need to Know About Measuring Wrench Time

Author: Matt Midas
Category: Enterprise Asset Management

Wrench time. It’s one of those hard to measure metrics and gets a fair bit of attention in the industry. Whether you work in Oil and Gas, Utilities and Power Generation, Facilities Management, or another industry, if you’re like most enterprise planning and scheduling professionals, you want to know: how do we boost wrench time?

We may be asking the wrong question.

Understanding maintenance wrench time

For most organizations, the average wrench time hovers around 25 - 35%. This is time when your maintenance technicians are working, tools in hand. They’re not waiting for parts, in meetings, on break, or traveling to and from job sites. Most of the work day, however, is consumed by “non-work” or non-wrench time tasks.

With a wrench time of 35%, for example, 3.5 hours out of a 10 hour day is spent working directly on tasks (e.g. replacing a leaking seal, repairing an air conditioning unit, etc.). The remaining 6.5? Not much value is being generated from it.  It’s not all “wasted” — but neither is it always utilized as efficiently as possible.

Increasing wrench time from 35% to 55% creates an average 57% jump in productivity. Let’s say you have a workforce of 40; they’ll be able to accomplish the same amount of work in the same amount of time as nearly 63 people with a wrench time of 55%. All at no additional cost for your organization.

So, what’s your wrench time? As maintenance planning and scheduling professionals, we’ve had the mantra, “You can’t manage what you don’t measure,” drilled into our heads. You need to measure wrench time if you want to improve it, right? Well…. It’s not quite that simple.

What you need to know about measuring wrench time

1. Measuring maintenance wrench time is hard!

Difficulty is not a reason to avoid measuring wrench time, but you should know what you’re getting yourself into. The challenge is that commonly used methods do not always yield accurate results. Let’s take a look:

Another reason self-reporting fails to give you an accurate picture of your wrench time: worry. Your people may believe that 35% is “bad” and that their jobs are in danger. This anxiety can make accurate reporting a challenge to say the least.

There are a few problems with this method too. Observations only record delays in the work area, which represent about half of all interruptions. And what about the folks who aren’t in the shop but are available for jobs?

Any number of factors can influence wrench times under DILO observation. It may not be a “typical” day, or a typical craftsperson, for that matter. In one wrench time study, a craftsperson completed a job in 3.5 hours — but wrench time was about 20 minutes.

In that study, the maintenance technician had to wait for instructions, for parts, for the operator to lockout-tagout the equipment he needed to work on and then go through the restarting procedure to check for leaks, etc..

It wasn’t as if he was twiddling his thumbs; these delays were unavoidable, but when wrench time is the end-all-be-all metric, it can generate incomplete data and a feeling of unease among your people (more on this in a moment).

Remember the Observer Effect too: observing a situation changes the situation. That is, craftspeople may not work or act as they normally do. They’ may feel “under the gun” to perform.

2. You may make your maintenance workers nervous.

Will they start carrying a wrench with them everywhere? Maybe not, but observing them may convey the wrong message if you’re not careful: that they’re not working hard enough. As a result, they may act in atypical ways. They may sweat the small delays over which they have little or no control. They may misrepresent work times. They will start to get antsy.

3. Measuring wrench time does not impact productivity.

But… really? Yes. Here’s why:

Y= f(X)

Y represents wrench time, high priority work orders, work orders completed per month, and mean time between failures (MTBF). You cannot affect Y directly.

X, however, is a different story. Here, it represents planning and scheduling. You can leverage X to influence Y. Palmer provides a useful analogy: You can’t affect your child’s grades in school (Y) but you can affect what time they go to bed and if they do their homework (X). Through X, you can indirectly impact Y.

So, what’s this mean?

By improving your planning and scheduling processes, you influence wrench time. More importantly, you’ll see greater productivity, more proactive work, fewer delays, and more efficient access to instructions, parts, materials, etc.

Remember that improving wrench time alone does not improve productivity or results. Say you have a craftsperson hammering away for eight hours but doing a subpar job. His wrench time may be phenomenal — but does that matter if the work is shoddy, inefficient, or incorrect?

4. A focus on measuring wrench time implies that all non-wrench time is wasted.

No, you don’t want your people spending hours in the truck traveling between jobs. No, you don’t want them waiting around for parts, taking unauthorized breaks, or completing a three-hour job in five. But just because a craftsperson does not have a tool in their hand doesn’t mean they’re not working or delivering value.

Think of it this way – the first law of thermodynamics sates that energy can neither be created nor destroyed. We have useful energy and wasted energy that comes out in the form of inefficiencies. Engineers are always trying to make the most efficient system, but there is always a loss in efficiency somewhere.

With wrench time, swap energy with time, and you understand that time can neither be created nor destroyed. Sure, you can always add more resources to get more hours, but that’s not the point, and it costs quite a bit!  A technician has a limited number of hours in the day: some are useful, and some are wasted. One of the goals of the maintenance organization should be to reduce the wasted or non-value-add time as much as possible. You will never eliminate it all together, but you sure can reduce it!

In today’s dynamic organizations, your people need time to think, plan, troubleshoot, problem-solve, give and receive clear instructions, enter data into their CMMS, attend critical meetings…. None of these count as “work” when it comes to measuring wrench time — but they can lead to greater productivity and enhanced results when it comes to putting wrench to nut and bolt.

Not all non-wrench time is wasted. A laser focus on this metric ignores critical functions that can move your organization forward.

5. Measuring wrench time: You don’t have to do it!

We’re going to ask you to make two solid assumptions: first, that your wrench time is probably industry-average (25-35%), and second, that it will increase if you create efficiencies in your planning and scheduling processes.

In fact, with proper maintenance planning and scheduling, you can increase wrench time to 65%. In an 8-hour day, this brings you from 2.8 hours (at 35% wrench time) to 5.2 hours.

Cut to the chase and focus on the Xs: planning and scheduling. This is where you’ll see the return on investment you need.

Wrench time is certainly a hot topic, but it is not the single most important metric to analyze, and depending on the needs of your organization, it may not be worth your time to try and measure. Start by asking the right questions: how do we improve productivity, reduce delays, and tackle more proactive work? Planning and scheduling is the answer.

Author: Matt Midas

Matt has been involved in the maintenance and reliability industry for over 30 years. A graduate of the US Merchant Marine Academy, he has served aboard US flag merchant vessels and upon graduation, he was commissioned in the US Navy and served aboard the USS Jesse L Brown, FF1089, where he was responsible for operations, maintenance, engineering, and safety programs.

Matt has worked at the Charleston Naval Shipyard where he was qualified as a nuclear engineer in the maintenance, repair and overhaul of S5W and S6G nuclear propulsion plants. He has also worked as a plant operations and maintenance manager where he was responsible for 186 facilities in Washington DC.

Matt has helped many customers leverage the data in EAM Systems to support the safe and reliable operations of their critical physical assets. He has also earned an MBA from Loyola College in Maryland.

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