Bluefield Round Table – Differences Between Fixed and Mobile Plant
May 20, 2020 8:19:15 AM
At Bluefield, we have the opportunity to work across a variety of asset classes. Being able to adapt between fixed and mobile assets is especially important to our work. So we asked some of our team the following question:
What differences (if any) do you find in managing fixed plant assets compared to mobile assets? Do you modify your approach when managing these different asset classes, and if so, how?
Significantly less opportunity for break-in work on fixed plant. You can bring most mobile fleet in if you have to, or have parts ready for the next opportunity, however with fixed plant (without duty/standby arrangement) you might get a window in unscheduled downtime but they are unpredictable and difficult to take advantage of - defect identification and planning are of primary importance to enable effective use of planned shutdowns.
Mobile Maintenance KPIs need to be carefully watched on a daily basis. Unlike Fixed plant low availability/reliability can sneak up on you. For example, if one truck is down (unscheduled) it does not get noticed a lot and if the workshop is not overflowing it does not draw attention. If however there is an endless stream of trucks coming in for unscheduled repair and not clogging up the workshop then the amount of unscheduled downtime tends to be overlooked until a weekly or monthly report indicates far mor loss of availability/reliability than was noticed.
With Fixed plant where things like mills and screens don't usually have redundant capacity the effect is immediate and noticeable. Quite different to mobile.
From a data & CMMS perspective, there are a few differences; you may be looking into utilizing different maintenance teams and locations for mobile equipment as you move that equipment to different sites or operations. With Fixed plant ones, you usually have the same maintenance team looking into the tasks on a frequency-based approach. You may also look at different material management strategies, and their corresponding lead times, based on where the equipment is located.
I have found that fixed plant suffers less from operational/operator variances and the accident damage incurred is less. I find it easier to extend component life with fixed plant components on such things as wear plates, pump internals etc because the component operating conditions are stable and consistent.
Stefan Van Der Linde
I generally find the fixed plant assets require greater collaboration with processing/metallurgy teams than mobile warrants as decisions made from a maintenance perspective can have disastrous consequences from a processing point of view and vice versa. Also due to the fact that there's a far greater number of assets in a fixed plant versus a mobile fleet you need to be more reliant on overall trends rather than getting spending a lot of time looking at one asset in particular.
Stefan has previously written about the importance of project readiness to minimising waste. Read the article here.
There is a lot less dynamics in a Fixed Plant because it is bolted down. Mobile plant has all sorts of operating and geographical dynamics that make it a much more changing environment. There are a lot more operators in a mobile operation (may be less when autonomous solutions become more common) and so immediately you have a lot more variable inputs and outputs.
From a maintenance perspective the big difference is the ability to monitor a fixed plant while it is operating, mobile fleet is getting lot more real time monitoring but it is harder to get into the structure and look for signs of movement or listen to noises and put your screwdriver against the bearing housing! Because of this we have tended to do corrective maintenance in fixed plants on a mainly condition based approach, while mobile has tended to be hours or time based. This is changing with better technology, but this is also helping fixed plants stay ahead.