Was looking for some advice on the servicing of plant. I work for a contractor and on average we are seeing 10% of plant being stood down due to mechanical issues, ie 10,000 hrs of plant 900 hrs total time stood. The plant is seeing relatively easy use being mainly used for top soil strips and moving spoil heaps. My question is what would be considered reasonable down time for a 14t Hitachi excavator, there is various models on site so a general overview would be great! Cheers in advance
If you are seeing 90% availability long-term even with new machines you need to let the rest of the industry into your secret. Based on my experience I would say anything above 80% year-on-year would be pretty good. Tip: Record the category of "waiting for parts" separately and analyze what % of the total downtime hours it is. These days it might take 1 hour to diagnose a problem then you wait a week for parts to fix it........
How far has availability slipped. The last 2 UH models I operated gave 100% availability and the last one did 11000hrs,neither had a easy life.
Lack of manpower is an issue these days too. Not easy to find reliable and skilled folks.
There must be a million different ways to calculate availability but in most commerical operations there is absolutely no chance that availability can be 100%. Put simply ALL downtime counts against availability, even planned servicing, planned repairs, machine inspections, refuelling, & greasing to name just a few. Any of those operations carried out during planned operational time counts against availability. Then you get to unplanned downtime which is a totally different kettle of prawns altogether. In its most basic form it's defined as the machine stopped itself as opposed to the maintenance/operation department planning to stop it. Can then be sub-divided into all sorts of categories such as lack of manpower, waiting on parts, etc, etc. See below. I'm assuming that the calculation below is somewhat similar to the one the OP is using to arrive at the 90% figure that started this discussion. And that's only the start of it. Then you get into more advanced metrics such as MTBF (Mean Time Between Failures), MTTR (Mean Time to Repair), Availability Index, Maintenance Ratio, Asset Utilization, etc, etc, ad infinitum.
My understanding of availability is when a machine isn't available for work because of breakdown. Maintenance conducted outside work hours isn't downtime if it's completed before the next start of work
I guess it depends on your definition of availability. I've seen machine listed as having better than 90% availability, some more than 95%. I seem to recall one of the stipulations in purchasing a D575 Komatsu was it needed to have 95 or 96% availability. One of the stipulations was the Komatsu dealer had to keep $1,000,000 in spare parts inventories. I would think like Tones if a machine is ready to work and doesn't breakdown during the scheduled shift(s) it would be 100% availability. As far as UH Hitachi's there's a reason they sold in huge numbers and basically made every other manufacturer have to play catch up.