It’s Your Turn: A Nation-wide Survey Raises Some Interesting

To gain an insight into current maintenance practices and procedures at operating mines, The Northern Miner Magazine recently conducted a maintenance survey of 30 medium-sized underground operations. About half of the operations responded and I would like to thank those participants. To summarize our findings: the typical medium-sized operation relies too heavily on verbal, rather than written, work requests; collects data but seldom analyzes it; and has made some efforts to introduce sophisticated predictive maintenance techniques.

One of the interesting findings of the survey is that most of us in maintenance dislike trashing old records. I suppose the records provide a level of comfort by their very existence. But while histories of key equipment repairs are being amassed by most maintenance departments, they aren’t being regularly analyzed. The history part of the so-called “history-and-analysis” process is being honored, the analysis part is being given short shrift. Like the proverbial horse and cart, however, the one component is essentially useless without the other. So if you have records, use them. If you don’t, begin collecting them. From the survey, we found there was only one operation where all work requests were written. Forty percent of the respondents used written work orders less than half the time. This follows a traditional, but unfortunate, pattern. Proper maintenance control is impossible without planning derived from written records (beginning with the initial work order). A historical analysis and follow-up corrective measures of any problem piece of machinery will quickly pay dividends in less downtime.

Here’s an example. I was hired as a consultant at a mine in Ontario. Its “running,” or unscheduled, repairs were swallowing up to 70% of the time required for all repair work. After instituting a proper history-and-analysis program with written work requests, we were first able to monitor the types of repair that tended to recur. After that initial identification of repair “hotspots,” we focused on specific repetitive breakdowns, eventually instituting more orderly, scheduled repairs before breakdown. Letting unscheduled repairs get out of hand is extremely debilitating to any maintenance department, as it disrupts orderly workflow. With less time devoted to running repairs, we could then concentrate on detailed history-and-analyses of various pieces of machinery. The result was a reduction in running repairs to 50% of total allocated repair time, and the trend is still pointing to further cuts in running repairs. I expect we will soon bring that running repair percentage down to 30%. The trick is to get running repairs under control so that they don’t disrupt planned repairs.

The types of records kept and how long they should be kept depend on the benefits to be gained. Such benefits include the ability to:

3 identify repairs that would not have been necessary if more care had been taken during the previous routine inspection;

3 investigate the cause of recurring problems;

3 evaluate the results of substitute or redesigned equipment; and

3 ensure that the times recorded to complete the jobs seem reasonable.

Keeping Deadlines

How long should maintenance records be kept? Three months is a good average retention time. By setting that deadline, records remain relatively current and vital. Aware of the deadline, maintenance personnel will never again regard that cardboard box of invoices and work orders dumped into a corner of the office as little more than a waste receptacle. It will become an integral part of the maintenance workflow. Maintenance managers should be flexible enough to extend or shorten the 3-month timeframe should a piece of equipment so warrant.

For the front-line foreman, the first step in organizing his part of the maintenance function is to have all work requests in written form. At most mines, the first-line foreman is distracted, harrassed and as close as anyone gets to indispensable. It is unfair and unrealistic to hold him responsible for timely completion of a succession of word-of-mouth repair jobs. This is crisis-oriented maintenance in action, and it leads to lost production and equipment abuse.

From the survey, we also discovered that a third of the respondents delegate control of repair parts to the maintenance department. Obviously, in Canadian mines, front-line supervisors are doing a lot of direct ordering and expediting. This should not be the case. The people who do the hands-on work identify the material, but procurement requires different expertise and is preferably left to the purchasing department. When the foreman is too directly involved, he spends too much time on the phone to vendors, expediting unstocked material for running repairs.

The survey also showed that high-tech maintenance tests such as wear particle oil analysis, infra-red radiation testing, vibration monitoring and ultrasound detection are creeping into mine maintenance. But not quickly enough. Wear particle oil analysis has spread, largely because of the efforts of oil companies. However, infra-red radiation, vibration monitoring and ultrasound detection are only slowly making in-roads. That’s unfortunate and ultimately costly. Predicting imminent failure is an accurate science now and, because of this, replacements can be scheduled. Historically, “breakdown maintenance” was common in the mining industry. Then preventive maintenance techniques were implemented. In time, the new predictive systems, which involve technologically advanced instruments, will be common to all mining operations. Our survey indicates that wide dissemination is still some time off.

Predictive Techniques

The survey also revealed that maintenance managers believe cost-cutting can be achieved more readily in material requirements (such as parts and so on) than in labor input. I can’t agree with that. I believe the labor component offers more hope for economizing. And I’m not suggesting “downsizing,” a euphemism for staff reductions. Real opportunity for cost control lies in streamlining job preparation time by maintenance personnel. An awful lot of lost time occurs while your maintenance mechanic receives instructions; plans, and requisitions for, materials; collects his wrenches and ratchet sets; arranges for equipment shutdown and lockout; breaks for coffee; and then finally settles down to work. At a mine I am consulting for, maintenance workers spend only four hours of an 8-hour shift on actual maintenance work; the rest involves preparatory routines. The goal is six hours per day of “effective time,” which is the time spent with tools actually in hand.

With regard to computerization, it appears that half of today’s mine maintenance systems have surpassed the manual stage. And this is as it should be, because maintenance management is information-oriented. At the top of a list of data that computers can easily handle are absenteeism, turnover, overtime, repetitive and non-repetitive work orders, and equipment meter hours. Among the practices that are useful for keeping maintenance under control are weekly schedules, backlog measurements, equipment histories and weekly reports on progress and trends. Obviously, the information age and maintenance are compatible.

That about wraps up the information I’ve gleaned from the survey responses. I would like to thank respondents again for their help and I hope this bit of feedback will prove useful.