Short repairs are repairs that a preventive maintenance (PM) person can do in less than 60 minutes, with the tools and materials that they carry, at the time that technician is working on the asset. These are complete repairs and are distinct from temporary repairs.
Why are short repairs so important? Because short repairs can be a simple change to the maintenance process that results in a major change to the worker’s productivity and simultaneously improves both reliability and Mean Time Before Failure (MTBF).
Non-Productive Activities
Here is the basic process a technician follows to perform a PM service on a truck or piece of equipment. To start, he gets get the job assignment and then heads to the supply/parts room to pick up any materials necessary for the job.
Next, the technician travels to the location of the truck/equipment or it is brought to him. He then locks out or tags out the truck/equipment. Now, work on the truck/equipment can begin.
Overhead
If you view the set up and non-productive time as overhead, then the PM ticket for that truck/equipment has already funded the overhead. Any additional work done at that time is pure productivity.
To put it another way, adding a mere 30 minutes of short repairs into an average day adds about 20 percent productivity to that day. Therefore, incorporating short repairs into your PM policies and procedures will improve your shop floor productivity.
Only One
There are 13 activities in a typical PM task list (see accompanying chart) but only one is productive. Thus, when we can do a second or third planned job on the same asset, we would add mostly to the “perform work” time.
This has been a scheduling “trick” for years. There are fleet maintenance computerized maintenance management systems (CMMS) that not only check if there are open items against an asset, but determine if there are any PMs either due now or in the next few days.
Consequently, when a job is scheduled for a particular asset, the scheduler no longer has to manually review the backlog for that asset to see if another job could be tagged on.
Work is Work
For every hour you pay for, the average PM worker does less than 20 minutes of direct maintenance work. This is based on extensive work sampling in numerous maintenance situations.
The question for the manager is: What is the worker doing when they are not doing maintenance? The second, and more important question, is: What can a manager do to the maintenance process to improve this situation?
Notice the use of the term “the maintenance process.” I did not say what action the manager could take against the supervisor or worker.
In all the studies, the actions of the PM worker were quantitatively less important than the process within which they operate. In fact, there is significant anecdotal evidence that the crazy patchwork of home-grown processes produce the negative attitudes occasionally seen in PM workers.
By “process,” I mean the steps needed to get work done. In this case, process can be defined as what the PM worker goes through to get materials, get job assignments and take over control of a truck/equipment. It is these processes that doom maintenance to low productivity, and it is the processes that must be changed.
Improvement in MTBF
With more efficient processes, the Mean Time Between Failures is improved simply because the number of incidents of downtime is lowered.
Take, for example, a downtime incident that is charged for a PM at which time a cracked hose is discovered is replaced. If we let the truck/equipment go back out with the cracked hose, it would eventually fail or be fixed at another time. This would result in an additional downtime incident, lowering the MTBF.
Many defects or deterioration observed during a PM inspection will sooner or later result in a failure and take the unit out of service. Adding the short repair, rather than writing up a corrective order, does away with the risk of a component failing before the asset comes back in for the scheduled service. This increases reliability, and thus, availability.
Since the short repair is done at the time of the PM, we are doing a reactive job with planned job levels of productivity.
The Rules
There are several chief rules to short repairs:
- Set a maximum time depending on the size of your facility and your type of equipment. Usually, the limit is 15 minutes to an hour.
- The repair must be able to be done safely with the tools, parts and materials that the PM person has with them.
- The technician must have the skills and knowledge to do the repair.
Disadvantages
There are several disadvantages to short repairs that should be known and managed. These include:
- The skill requirement for PM people for short repairs is significantly higher than for just a PM.
- Short repairs require significant judgment so the short repair doesn’t turn into a long repair or isn’t too troublesome.
- You need to accept the fact that short repairs cause schedule disruptions.
In my next column, I will offer suggestions for organizing a short repair set up.
Joel Levitt is director of international projects for Life Cycle Engineering (www.lce.com), an organization that provides consulting, engineering, applied technology and education solutions that deliver lasting results. Previously, he was president of Springfield Resources (www.maintenancetraining.com), a management consulting firm.
