Stretch SMED Consulting

I arrived in Spain not knowing who the client was or what was expected of me.  I was to help conduct a workshop with the European branch of the Kaizen Institute. My fluency in Spanish along with some experience in kaizen consulting got me the job.

In the opening lecture, I was introduced to 50 to 60 people as a leading expert in SMED (single minute exchange of dies).  I have facilitated five or six workshops to reduce the time to changeover equipment from one product to another.  I seem to have a knack to help a workshop team cut changeover time in half, starting from an hour and an half to two hours. I have a process that has always worked so far. I did not feel like an expert.

The plant was actually a series of plants, with a stamping plant at one end and a final assembly plant at the other.  The products were automobiles. I would be facilitating one of three workshops. Mine would be in stamping.

The Superintendent of the Stamping Plant led me to his spacious office and invited me to sit.

“Bob, I am really looking forward to what you can do with this line, we have been working on it for months, and taken hours out of the changeover. It now takes under one hour.”

“We’ll have to see what the team can do,” I said.  I hope my process works, I thought.

We gathered the team, seven Spanish supervisors, mid-level managers and engineers, and an equal number who had come just for the workshop from Germany.  I don’t speak German. The Germans did not speak Spanish but did speak English.  I was going to have to say everything in Spanish and English.

“Let’s go look at the line we will be watching.”  We swarmed out to an area the size of a football field on which four presses three stories tall were linked together by transfers.  The sheets of steel went in at one end.  The side of a car came out the other.  The entire process had four or five operators.  It seemed to be running fine.

A knot formed in my stomach.  I knew nothing about the operation of these presses, or their changeover process.

We gathered in our meeting room for me to provide an introduction to SMED and explain the activities of the team.  Our job was to time the internal time of the changeover, from last good piece to the first good piece of a series of good pieces. The external time was composed of activities done in preparation for the changeover, and things that could be done after the line was up and running again.  We would identify activities taking internal time that could be moved to external time, before the equipment was shut down or after it was up and running again.

We would look for waste, activity that was not adding value to the changeover; hunting through a pile of nuts and bolts for one that was the right size; putting twenty turns to a nut, before reaching the last partial turn that torques the nut tight.

We would watch the people doing the changeover and capture their movements on a spaghetti diagram, on a layout of the equipment and surrounding areas.  A pair of people would write down as much as they could that happened during the time the machine was down, keeping a running tally of the elapsed time in the left margin. Everyone would try to make notes of ideas that could eliminate waste or make internal time into external time.

We went to observe our first changeover.  We would not be able to watch the entire process, so we focused on one press and its transfer to the next.  The last good piece was ejected.  We started the stopwatches.  The exchange of the dies themselves was almost entirely automatic. The existing die was released from hydraulic clamps.  It rolled out on a track.  The new die waited on the track on the other side.  It rolled in and the hydraulic clamps closed.

On the transfers there were dozens of fixtures that moved the part from one stamping press to the next.  A team swarmed over the area, changing fixtures and adjusting their heights. The spaghetti diagrams looked like bowls of spaghetti. The written records captured a lot of activity that did not add value.  The team participants had many good ideas.

The first changeover took around 49 minutes. The team standardized procedures and sequences and fabricated some special tools to reduce the time to 30 minutes the next time.  The final observed changeover time was down to 22 minutes, after further tool modifications and better pre-staging of tools and fixtures. The Spanish members of the team felt that they knew what they needed to do to get under ten minutes, including by eliminating some tools altogether.

The process worked.

The Superintendent of the Machining Plant was delighted with the results, and he felt that the participants had learned a useful process that they would apply to other operations.  I never got back to that plant.  I wonder if they got the line changeover under ten minutes. How successful they were at applying the process to other operations?

I never felt that nervous again about doing a changeover workshop.  I never again did one with such enormous equipment, although I have done many involving stamping presses.