The following is adapted from Simplifying Mining Maintenance.
There are many explanations for why mines have excessive unscheduled and reactive downtime. Some issues relate to defect detection, reporting and consistent us of the CMMS, while others deal with work quality or working together as a team. All of these issues, once spotted, can be corrected with the right approach and avoided in the future.
In this article, we’ll look at two major problems surrounding maintenance work. As you’ll see, these issues aren’t always easy to fix, but the effort is well worth the payoff.
Problem #1: Work gets done to poor quality standards
This problem refers to the technical craftsmanship of corrective, preventive or proactive work. Too often, someone replacing a brake assembly, hydraulic hose, engine, or some other component does an inadequate job and, in doing so, creates future issues.
There is no good excuse for substandard work.
The original equipment manufacturer (OEM) generally provides mechanics a procedure for doing the job correctly, so there should always be specific quality information to ensure bolts are torqued correctly and that there is proper fitment and setup. (Sometimes the site will need to make the procedure more applicable to their context, however the OEM information is a good place to start).
Welds require high-quality standards. Welds are prone to re-cracking if correct pre- and post-heating standards are not employed and the weld surface is not finished properly. However, many mine welders rarely consider the required quality standards.
Years ago, we welded keepers on dragline bucket teeth, chains and pins. These are all bolted today, but they used to be welded and they frequently would fall out.
We didn’t bother with root-cause analysis back then. We just engaged the mechanical engineer, who then worked with the welder to find out that the keepers weren’t preheated before being welded. We made a change to the acceptable standard and when the welders started preheating in this way, the unscheduled downtime plummeted—all because we used correct welding procedures on a simple welded keeper.
Solution #1: Documentation and daily quality discussions
These examples illustrate the value of having a culture of high quality.
Maintenance team members must also agree to follow the written procedures and documents, whether it is the remove-and-install (R&I) documentation, a QA/QC-type document, or a PM inspection checklist. In addition, maintainers must alert leadership when they think documents are wrong. Ticking boxes when the work is not done adequately is of no value. Team members must talk about instances when work is poorly executed. Everyone must care about quality. Do it once, and do it right.
Temporary repairs must be done at times and are OK as long as you raise a subsequent action in the CMMS to ensure a permanent repair is made. Temporary repairs that are not raised and corrected permanently lead to future breakdowns.
We have helped many sites change the execution standards or change the culture that accepts low standards. There is no magic bullet here. It is more important that teams have a desire to improve and face reality, then the teams will find a solution.
Some of the mechanisms that our clients have used to enable this cultural shift include using a quality cross to track execution standards and implementing a daily quality discussion into the shift start meeting. In these meetings it is important to recognise good quality execution standards and highlight poor quality examples so that the standards are continually raised. This process is very similar to the safety improvement journey that our industry has been on for 20 years.
In addition to raising the standards, this daily discussion allows tradies to talk about technical issues and improve their technical knowledge.
Problem #2: Jobs in the system get lost and aren’t completed
This problem occurs when someone raises a defect in the system but no one schedules the work and a breakdown results. This often happens when the people looking at the backlog/forward log overlook the defect. Sometimes they filter the open work orders in the system and do not look at all of them, so these defects get lost in the system.
One time I saw an “out of service” tag on a dozer access ladder. The dozer was in for scheduled maintenance but the broken ladder wasn’t part of that repair plan.
I learned that the ladder had been out of service for six months, but planners were only searching for work orders from the last three months. They didn’t see it.
Not only could this have resulted in an unscheduled downtime event, it could also cause operations to lose confidence in the maintenance team.
At some mines, jobs get lost in the noise. Some jobs are completed but not closed out. To test for this at a new site, I pick a random machine or part of the plant and organise a meeting with the planner, supervisor, superintendent, and tradespeople to review every single job that’s in the system for that particular machine or plant area.
I don’t expect one person to know everything that must be done to each machine. However, for each job in the system, at least one person from this group must know the details. As a team, they should be aware of everything related to that equipment.
It is not uncommon to ask about the status of each job and hear lots of maybes or nothing at all. Silence. No one knows. There are often work orders that have been raised, and no one can say whether that work was completed.
Looking at all of the work orders in the system like this can be, for the assembled group, a realisation that their process of handling work orders is out of control.
Solution #2: Go through the worklog every week
Everyone must be on the same page to solve this problem. Maintenance supervisors, the superintendent, planner, and operations team must agree on a plan and priorities for the next scheduled period and be sure that all jobs are reviewed. The maintenance and operations team must go through the backlog or forward log every week.
This approach may sound like telling someone that the solution to not suffocating is breathing. Unfortunately, these basic problems repeatedly occur.
Meetings and detailed procedures won’t help; people won’t be motivated to solve these problems unless they take ownership of the process and the outcomes.
For more advice on avoiding breakdowns and downtime in your mine, you can find Simplifying Mining Maintenance on Amazon, Google ebooks or simplifyingminingmaintenance.com.
Gerard Wood is one of the mining industry’s foremost authorities on proper mining equipment maintenance. In his long career, Wood has been all over the world, working his way up from an electrician’s apprentice to a maintenance manager with advanced degrees in electrical engineering and business. As managing director for Bluefield AMS, Wood helps the world’s largest mining companies keep their machines running with a simple, practical approach that saves money and improves equipment reliability.