Working in mining and minerals, I am always amazed at how companies maintain some equipment effectively, yet other equipment on the same site, are not properly maintained at all.
I will use the most common example of ‘effective’ maintenance that occur: SME servicing. Most companies maintain SME to the book, usually based on 250 hour service intervals. And these equipment are mostly reliable due to the maintenance being performed.
But why do companies stick to these service intervals? It gives a sense of control, comfort and sometimes they get a warranty from the OEM as well.
Have you ever considered why OEM’s are willing to back their product and maintenance regime? To them this is the lowest risk solution, plus it gives them a higher turnover in selling spares. So for the OEM this is a win-win-win situation. Lower risk, higher turnover and better reputation.
Fast forward to fixed plant, and companies have unpredictable availability, unreliable product delivery and no real maintenance regime. Why?
How many fixed plants have a maintenance regime based exactly on OEM specification, and sticks to it as religiously as with SME? Not many that I know of. Why is that? Too high a cost? Too much effort? Or is there a lack of understanding that fixed plant and SME are all the same? Usually the cost of maintenance is too high for fixed plant. Which is fine – but then understand that the reliability will also be lower than SME.
Most of the OEM maintenance regimes are built on total reliability – yet the impact of a failure is very low. Is it then really worth such an intense maintenance regime?
Furthermore, when cost pressures are on, maintenance budgets and personnel are the first to suffer. Fixed plant maintenance crews are reduced, maintenance plans are ‘optimised’ with the expectation that the plant will continue with high reliability. Rarely does SME maintenance get cut, and most of the times when it does get cut, it is with little detrimental effect to the reliability of the equipment.
So, what can be done? A best practice method lies somewhere in between. If you need an optimised maintenance regime, you need to evaluate the impact of the failure. That will then determine the maintenance requirement.
Your maintenance should be based on the impact (safety, environment, cost to repair, loss of revenue) vs. the cost to maintain. If a predictive maintenance regime cost you 5 labour hours every week, but the failure will only cost the equivalent of 4 hours total, is it then worth doing the predictive maintenance?
The decision you need to make is whether you want effective maintenance or highly predictable reliability? For most businesses, the best solution is somewhere in the middle, you just need to dig through the dirt.