Q: Some of our machines are not being used every day on the demand of the product. So, I don’t evaluate those machines when they remain idle. But, as per my boss, those idle machines should also be evaluated (i.e. OEE =0) and should be presented in monthly graphical reports. Is it correct to calculate OEE of those machines while they are not running?
Arno Koch • OEE is a shop floor tool to identify losses on effectiveness of the equipment.
Whenever the machine is un-scheduled because there is no demand (a good decision, specially if you compare it to producing stock) this is not a problem of the equipment yet a problem of the operation; i.e. there is a sales problem. However this problem pops up at the machine.
This is the reason why there are 3 measures based on the same data:
- OEE (Overall EQUIPMENT Effectiveness) is being calculated over the time the equipment is normally supposed to be scheduled; usually this equals the regular shift-time (ie 510 minutes in an 8 hrs operation -480 working minutes + 30 min break). If the machine has to be un-scheduled due to no-demand, this time in substracted from the OEE time, yet it will become visible in the next measure:
- OOE (Overall OPERATIONS Effectiveness) is basically the same as OEE, yet it also includes un-scheduled times like whenever the machine is not running due to a lack of demand.
- Ultimately TEEP is calculated. Again basically the same as the normal OEE yet it takes 24/7 as maximum time. So in a full shift operation, the TEEP will be the same as the OEE.