Availability Calculation for monitoring Overall Equipment Efficiency

[quick_silver]

hi to all,

I was assigned in developing a worksheet monitoring on OEE. Currently I was doing the Availability calculations. Our plant is very huge there were about 10 departments and roughly 6 hectares(roofed). My superiors wanted to determine the line availability.
1)So my calculations are based on the downtime monitoring of one line. But i was using the rated speed of the slowest machine of the line.
2) A department is consists of several similar lines, I calculated the departments line Availability by using the sum of the downtimes of all lines and the sum of the gross operating hrs less the scheduled downtime. Is this right?
3) There were some departments that have spare machine. I consider it 100% on availability but i think they will have an issue on machine utilization. each area has a spare machine for this department because if the machine will breakdown and no spare it would mean stop production of the whole plant. How is the utilization calculated? am i right that this is not captured in the OEE?

any inputs will be greatly appreciated..Thanks

 

[quick_silver]

Re: Availability calculation

just an additional info..

one of the line in charge told me that their machine is 100% efficient no speed loss, because the rated speed is the actual speed..is this possible? he was telling me that the rated speed is just the same because of the machine does not have any VFD...can't wait to see their data...He was telling me though that their monitoring has a big percent unaccounted. I told him that the % unaccounted seen on the efficiency part and not on the availability and told him that they must see to it that it is accurate to minimize the unaccounted.

 

[KLDLetts - 2012]

Re: Availability calculation

I would recommend doing each line separately, and with only the equipment that is a "permanent" part of the line (provided that the spares are used only if the other piece of equipment has failed, and are equal in name plate capacity).
You should, in my opinion, also use the highest rated nameplate capacity on the line (or choose a defensible piece of equipment, in our filling operation we really care about how fast we can fill, and aren't too concerned if we are technically under-utilizing our box taper).

Without knowing your process or the operator in question, I would probably guess that you're being fed baloney -- unless they produce the nameplate capacity on that machine all day, every day without any breaks or break downs.