OEE (Overall Equipment Efficiency) and Downtime

[phil1234]

What we have decided to do is to account for the machines 24/7/365 = 100% utilisation, which makes sense. (This sort of incorporates TEEP as well), all downtimes will be noted to make up the balance of 100% minus run time.
Our OEE will only be 100% if we work 24/7/365 with no downtimes (if throughput and quality = 100%), so running 3 x 8 hour shifts 5 days a week, the max OEE would be (3x8x5)/(24x7) = 71.4% and so on.
We will achieve a higher OEE by working "overtime" and our $ turnover will be correspondingly higher.

 

[adrianpask - 2011]

Hi Phil, great logic - see where you're going with that. Many sites would call that measure "Asset Utilisation" and would not normally measure it below senior manager level based on the principle that some sites don't want teams to have a lower number because they have no volume to produce. Check out this diagram and see what you think - it's our OEE 6 loss model: http://oeejourney.optimumfx.com/wp-content/uploads/oee_white3.jpg

Ade.

 

[D Scott G]

Greetings;

I see many posts about OEE use, but not real direction for the posted issue. What I see as being asked is what "OEE rules" do you use? We use the above posted formula but with the Company twists. The rules are not posted anywhere at work and thru many questions some have been understood.

Mainly for your question if a machine goes down during a shift we assign the proper downtime code for the issue and take the OEE hit. The next shift we do not enter anything into our system or use an unscheduled code and we do not take a hit OEE wise. This is not side stepping our system because I also run a machine utilization report that accounts for the lost production time.

I would use the utilization report for their accounting of the $25,000 that they spent.

OEE Rant:
Too much focus is on the OEE % and not enough on the three factors that calculate our loved OEE %. This is what I mean above by the "company twists" each company has different ways to calculate the three variables and understanding them will help you to understand the root cause of a machines low OEE. I myself last year while investigating low OEE found availability to be the root cause. The next step was to focus on what affects the availability calculations or not and it was found that the PM codes and the not scheduled code does not hurt our OEE. Yes I know I just also gave the secret to cheat on ....aww I will let them figure that out but I think the positive outweighs the negs. Our PM crews, for the mold and machines, were not showing their downtime correctly or at all thus whacking my OEE adversely.

OK enough of the rant, I'm out.




Scott

 

[phil1234]

Hi Scott
I agree with you: There should be a rule book issued by APICS or some one else which covers all issues.
We are going to implement our own system, agreed to by all, in the next financial year (July).

 

[adrianpask - 2011]

Spot on Scott - completely agree that the devil is in the loss not the output. Here's a challenge - take your beloved 3 loss up to 6 loss; it makes an awesome difference in the identification of issues. In my sites we capture all losses like this:

1. Minor stops (stops to the critical machine <5min)
2. Major stops (stops to the critical machine >5min)
3. Speed loss (loss in speed when the machine is running i.e. excluding stop time)
These 3 are your perfromance measure

4. Quality loss in running (reject count turned into time)
5. Quality loss in startuo (reject count and loss time on startup - in my bottling and food plants i don't tend to use this category as the downtime is captured in planned downtime and losses 1-3 normally)
These are your quality losses

6. Planned downtime (any event that is not an unplanned stop)
Your availability measure.

We then tend to exclude from OEE the time when the site has no production plan (calling it not required for production - NRFP). This measure is captured in a seperate asset utilisation KPI.

Regards,

Adrian.

 

[Mikael]

Re: OEE (Overall Equipment Effectiveness) and Downtime

Thx, time goes, the link to the workgroup does not work anymore.

 

[Stijloor]

Re: OEE (Overall Equipment Effectiveness) and Downtime

Thx, time goes, the link to the workgroup does not work anymore.

Will this link work for you?

http://www.worksmanagement.co.uk/news/put-oee-higher-up-the-plant-floor-agenda/2160/

You can search the site if you wish.

 

[Mikael]

Re: OEE (Overall Equipment Effectiveness) and Downtime

An article from 2003, hmm...