Production Sacrificed in the Name of Changeovers

Is it ever OK to value the number of changeovers you do in a day over your production numbers?  I say no.

I was with a customer recently that did just this.  The customer has done a great job of setting production goals for a press per shift.  On the production board, they write the production numbers in green if the meet or exceed the goal and in red if they do not.

Normally, this is great.  The customer is making the problem visible and easy to see.  Then I noticed that a number below the goal was written in green.  So, I asked about it.  The customer replied the operator did a lot of changeovers that day so we give them green if they do so many changeovers but don’t hit the production goal because the changeovers eat up a lot of their time.

The managers were giving a built in excuse for the operators to not meet the production goal.  If the goal was set with capability and meeting customer demand, then why is it alright to produce anything less than the goal?  This tells me they are not putting a big enough emphasis on changeover reduction.

The question should be changed to understand what is the changeover time needed.  If the largest number of changeovers I need to do in a shift is X and I am accounting for time T to do the changeovers, then my changeover time target should equal T/X.  Example: I allow 1 hour for changeovers and I need to be able to handle 10 changeovers in a day, then my changeover time target should be (60 min) / (10 changeovers) or 6 min/changeover.

If my current changeover time is more than 6 minutes, then I should be doing some sort of SMED (Single Minute Exchange of Die) activity to get the time to 6 minutes or less.

The number of changeovers can never be an excuse for why it is ok not to hit a production goal.  The mindset should be to continue to reduce the changeover time and ideally eliminate the changeover time so the production goals can be met.

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Posted on April 4, 2011, in Customer Focus, Flip The Thinking, Manufacturing, Tools, Waste and tagged , , , , , , . Bookmark the permalink. 2 Comments.

  1. I’m shocked just thinking about the logic of counting the number of change overs. BTW – I prefer performance to sequence (especially in a press shop).

    The notion that the management would even allow the number of change overs to account for lack luster performance is a clear indicator that “they don’t get it!”

    While I agree they could use SMED to reduce change over time, I think they need just as much help understanding what it really means to achieve performance to schedule objectives.

    I’m always concerned when a team attempts to rationalize poor performance and even more so when management accepts it. It pains me to think how much other waste may exist.

    I wonder if they would ever get to the point to consider using a heijunka board. There’s a target that’s tough to beat.

    Excellent post.

  2. Matt,

    This is surprising to me as well. I don’t want to sound too critical since I’m not there to see it but I’ll suggest that the reason for doing the change-over is to make production on a different item….Even if you planned to be down for the change-over, you are still down.

    Anyway, this is the reason why those folks that defined OEE have the change-overs count against the efficiency number. This is in contrast with the traditional way of calculating Production Efficiencies. The advantage is that it illustrates the opportunity for improvements.

    Good post. You illustrate the points well.

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