Ask a plant manager how hard the maintenance crew works, and you will usually get a straight answer: hard. Long hours, weekend call-ins, always something on fire. So the number tends to land like a slap.
In most plants, a technician spends only 25 to 35 percent of the day actually turning a wrench. Best-in-class sits at 55 to 65 percent. That is not a small gap. At 55 percent wrench time you get roughly a 57 percent jump in productivity out of the same people, as my friend Doc Palmer has shown for years.
Here is the part that matters. That gap is not a people problem.
Wrench time is the share of a technician's day spent actually performing work, not traveling, waiting, or hunting for parts and information. A typical plant runs at 25 to 35 percent. Best-in-class runs at 55 to 65 percent. Getting from the low end to 55 percent yields roughly a 57 percent gain in productivity from the same crew, with no new hires.
Picture a millwright at a packaging plant. Call him Dave. Dave clocks in ready to work. Then the morning happens to him.
He waits on the work order to come through. He walks to the storeroom and hunts for the parts, some of which are not where the system says they are. He tracks down the one person who can lock out and release the line. He digs for the sheet that tells him how this job is supposed to go, because the last person who did it kept it in their head. By the time the equipment is actually his, half the shift is gone.
Dave did not drag his feet. He spent his morning waiting on everyone else. Multiply Dave across a crew and across a year, and you have found your missing wrench time.
When I evaluate a site, the lost time almost always sorts into four buckets. These are the avoidable delays:
Waiting for the equipment to become available. Production is running it, nobody scheduled the window, and the technician stands by.
Looking for parts and materials. Trips to the storeroom, wrong parts, parts not in stock, no kit staged for the job.
Searching for information. No procedure, no job steps, no bill of materials. The knowledge lives in one veteran's head.
Getting pulled from one job to another and having to restart the first. Ineffective prioritizing, so a half-finished job gets abandoned and re-started later at full cost.
Notice that not one of those is the technician working too slowly. Every one is a coordination failure that happens before the wrench ever touches the bolt.
Planning and scheduling is not paperwork. It is the discipline of removing those four delays before the technician walks up to the job. On average, every hour spent planning eliminates three to five hours of execution, because the waiting, the hunting, and the searching get handled in advance.
A few moves do most of the work:
Kit and stage the materials. Get the right parts to the job before it starts. If nothing else, it gives the technician a head start instead of a scavenger hunt.
Build reusable job plans. Maintenance is repetitive. You will work on that same asset again in six months to two years. Write the plan once, improve it each time, and stop rebuilding knowledge from scratch.
Schedule against all the labor, and protect the window. Schedule 100 percent of the available hours and coordinate equipment access up front, so the crew is not standing around waiting for a line to free up.
You do not need a great plan on all 400 jobs. You need a good plan, estimated hours, crafts, and materials, on all of them, and a great plan on the handful of complex or repeating jobs that pay it back for years.
More wrench time is only half the return. The other half is fewer failures.
Roughly 70 percent of equipment failures are self-induced, the result of how the work gets done, not bad luck. Winston Ledet, in Don't Just Fix It, Improve It, put a finer point on it: poor work behaviors drive 84 percent of failures. When you plan a job properly, you are not just saving the technician a trip to the storeroom. You are handing them the procedure, the right parts, and the time to do it precisely. Precise, standardized work pushes that failure rate down.
So the same discipline that recovers your wrench time also stops the breakdowns that stole it in the first place. That is the compounding return: more work done, and less rework to do.
One packaging facility I know was drowning in overdue work orders. When they looked closely, the technicians were spending most of their time waiting on parts, tools, and equipment access. The same four delays. They put one dedicated planner in place. Wrench time climbed from 30 percent to 55 percent. No new hires. Overtime fell 20 percent. Same crew, close to double the useful work.
Put it in headcount terms. Take four technicians from 35 to 55 percent wrench time and you have effectively gained the output of 6.28 technicians. You did not hire two people. You stopped wasting the two you already had.
That is the quiet leverage most plants are sitting on. It does not require a bigger budget or a new headcount request. It requires taking the delays seriously.
Before you change anything, find out which delay is costing you most, because it is not the same in every plant. That is how wrench time moves, not with a slogan, with one delay removed at a time.
The four delays are not the same in every plant, and neither is the fix. Three of them, the equipment, the information, and the constant reprioritizing, come down to how the work gets planned and scheduled. That is the heart of our Maintenance Planning and Scheduling course. The fourth, the scramble for parts, lives in the storeroom, which is why we built a separate Storeroom and Materials Management course to turn it from a place people hunt into a partner that has the right parts staged and ready.
What is wrench time?
Wrench time is the portion of a technician's shift spent actually doing maintenance work, not traveling, waiting for equipment, or looking for parts and information. It is usually measured with a sampling study across a crew.
What is a good wrench time percentage?
Most plants run at 25 to 35 percent. Best-in-class sits at 55 to 65 percent. At 55 percent you get roughly a 57 percent productivity gain from the same crew.
How do you increase wrench time?
Remove the four avoidable delays before the job starts: schedule the equipment window, kit and stage the parts, give the technician written steps and a bill of materials, and stop pulling people off jobs mid-task. This is the work of planning and scheduling. On average, every hour of planning saves three to five hours of execution.