Comments on: How metrics like OEE often dictate behavior

By: G O'Neill

G O'Neill — Wed, 21 May 2008 03:39:27 +0000

Thanks for the comments guys, definitely some insights for me there.

By: Lester Sutherland

Lester Sutherland — Tue, 13 May 2008 12:53:51 +0000

Running overtime has less waste since it is only used when needed rather than built in as a waste. The issue is your relationship with your workers. If you have day care onsite and the OT is not a daily thing it is a more waste free and acceptable process.

By: Mark Graban

Mark Graban — Tue, 13 May 2008 11:20:45 +0000

If you just divide cycle time by takt time, you’re going to need 100% efficiency… not likely even in the best of processes. It’s better to use a factor (I’ve seen 80% or 90% used) to account for “normal” downtime (even in a “lean line”). You need to be able to run faster than takt to make up for downtime you do incur (or be prepared to run overtime to make it up).

By: Lester Sutherland

Lester Sutherland — Mon, 12 May 2008 20:31:57 +0000

Ron,
I agree that OEE is not the metric to use for most situations. If the equipment was a bottleneck or constraint OEE would make sense. It sounds like the original question was should he increase the performance (speed) indicator to the new higher speed, or be able to run faster and get a “boost” in the measureable because his increased speed 110% would offset some other problem like availability or quality. The old game the numbers issue. I always answer that the best speed is whatever the best achievable speed is…. But don’t use the measureable where it does not make sense.

By: Paul Cary

Paul Cary — Mon, 12 May 2008 19:55:49 +0000

I have used time card racks for work centers or capital equip, each slot representing a time increment i.e. 1 hr. place the order in the slot and if the estimated time is 3 hrs. leave 2 slots these blank plus the slot would equal 3 hrs. of capacity.

By: Ron Pereira

Ron Pereira — Mon, 12 May 2008 19:51:27 +0000

Oh… I like that Quinn! Let me see what me and my Pereira Lean Production Team can come up (aka my kids)!

By: Quinn

Quinn — Mon, 12 May 2008 19:43:25 +0000

Perhaps for a future video you could illustrate the principle of heijunka or level loading. Demonstrating how it could be applied to a varied product line of say envelopes stuffed with red, white or blue paper. (envelope size could also be a variable). Just a thought in response to your request for possible future video ideas.

By: Mike Z

Mike Z — Mon, 12 May 2008 18:08:22 +0000

Ron alluded to the point that the business model should not be driven off of OEE scores. It needs to be said that Lean and Six Sigma provide dozens of measurements that can be used as estimations versus a baseline or target rather than an evaluation criterion or score.

Your reader should be trending the OEE vs. “Required” OEE rather than desired OEE. If used for an evaluation of the line’s productivity, it needs to be measured on a daily basis for a discrete manufacturer. Some days only require 30% yield while others demand a 85% yield. This can support your mixed constraint scheduling process if you’re using one as well. We have instituted a similar scheme by determining staffing levels on a daily basis in assembly based on the “Required OEE” and distributing our flexible staff to areas with a higher “Required OEE” for that day.

By: Ron Pereira

Ron Pereira — Mon, 12 May 2008 15:39:03 +0000

Thanks Paul. So you are saying this planned downtime is deducted off the top to ensure they are not penalyzed in their OEE measurement, right?

By: Paul Cary

Paul Cary — Mon, 12 May 2008 13:35:07 +0000

I also think that if demand is less than available capacity, you may have “scheduled downtime” deducted from the overall calculation. This method may work better with a piece of capitalized equipment rather than a production lime.