A Step-By-Step Process for a Changeover Workshop (Part 1)

Changeovers take time. Different models need different dies, different fixtures, and different settings. Usually, all of these have to be changed. During the changeover process, I’m making nothing. I am very tempted to make more than I need when I have everything set and ready to run.  I may only need 100, but I will go ahead an make 500 or 1,000 units, because at least the machine was productive, and I can put the extra pieces on the shelf, ready for when they are needed.

Then they sit on the shelf.  I didn’t need them when I made them. I t can turn out that now that I have made them, I won’t need them for a long time.  Depending on what “they” are they can get dirty or damaged just from sitting.  The can rust or otherwise deteriorate.  In any case, I’d better keep track of them, because I need to know where I put them when I need them.  So someone will have to keep (or enter into the system) an accurate record of how may I stored and where I put them.

When I need some again, I need to remember to look up how many I have already and where I put them.  Sometimes we go ahead and make a fresh batch because we forget that days, weeks, even months ago, we made some of these.

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.

Go to Gemba

I was facilitating a workshop in a large automobile assembly plant in Great Britain. The factory was a part of a large, western, multinational auto manufacturer. In my group, one of three or four, there were participants from several other parts of Europe and the United States.  This was to be a big learning experience for the entire corporation.

Everyone had gone through a day of lecture and discussion about the principles, concepts and some of the methodologies used in kaizen. Finally, on day two, all of the participants were sent out to the factory to find ways to improve parts of the assembly line. 

Each of the workshop groups was facilitatied by a consultant.  My group was to focus on the installation of the headliners in cars that came down the line.

Every group was given a meeting room.  Our group had about ten people. We gathered in our assigned meeting room and sat around a round table on which were piled a number of drawings of the shop floor and the section in which we would be working, as well as several stacks of printouts with data on throughput time, defect rates, line down-time, and probably several other trends which I do not remember.

Getting these managers out of the meeting room proved to be difficult.  They wanted to “study the data.”  I had to become more and more insistent that we go out to the section of the line we had been assigned to us. We needed to go to gemba (gemba means the “real place,” used in kaizen to refer to the place where value is added) to  Identify waste, which we had learned about the day before. I told the team that after that, we could get away from the noise for a bit, back in the conference room and discuss possible improvements.

What Get’s In the Way of Successful Kaizen?

A dirty little secret is that kaizen efforts often go nowhere, or don’t go very far. In too many cases I have seen very successful kaizen workshops or kaizen blitzes seem to be huge successes, only to have them fade within months or even weeks.

 What do I mean by successful workshops?  A team focuses on a work group or operation.  With the help of a facilitator they identify and figure out how to eliminate waste. The facilitator, who may or may not be an outside consultant, teaches how to look for waste and the strategies to accomplish its elimination. These include moving operations closer together, moving the operations into a U-shaped cell, doing away with batch processing and putting one-piece-flow in its place, and balancing the operation with takt time and cycle time studies, to name a few. The team figures how to accomplish these ideas in this particular case. 

At the end of the workshop, there is a dramatically different situation.  Fewer people are required to produce the same amount. Throughput time is drastically reduced.  Quality is documented to have substantially improved. Everyone agrees; this is better.  This is great stuff.  (Another example might be a SMED workshop that cuts changeover time from over two hours to forty five minutes.)

Quality Process and Quality Results

How do we assure that our customers receive the highest possible quality in our products?  The first thing that comes to many people’s minds is that we need to have plenty of inspection.  Defective products will get made and we need to catch them before they get to the customer.

Unfortunately, inspection (as well as various kinds of testing) does not catch every defect. No inspection process catches every defect.  Many let 20%, 30% and more escape.  Inspections can also catch products that turn out not to be defective.

In workshops, we demonstrate the unreliability of inspection by having each participant independently count the number of a certain letter (for example, “e”) that can be found in a text. All counters do not come up with the same number. If the letter were a defect, some would not be caught in the inspection process.

Inspection does not add value.  It only catches some of the defective products and leads us to other work that does not add value either, but does add cost.

Why Not Manufacture in Easy Batches?

During a workshop, a manager resisted the idea that batches are always to be avoided if possible.  He used the example of paying his bills by check (this was before the days of online bill-paying). It was easiest for him, he said, to sit down at the kitchen table, open all the bills and take them out, write all the checks, stuff all the envelopes, put stamps on all the envelopes and drop them in the mail.

I asked the group if there was anyone present who had ever sent the wrong check to a payee.  A couple of people admitted that it had happened to them.

If you practice one-piece-flow, processing one unit at a time – in this case one bill—you practically eliminate that particular mistake.  You open one envelope, read the bill, write the check, put it in the envelope with the bill stub, seal the envelope and put a stamp on it.  If you wait to put stamps on the envelopes until all have been sealed and stacked, there is more of a chance of skipping an envelope and mailing it without a stamp.

Takt Time

One of the concepts used by companies that are moving toward leaner operations is takt time.  It is also a concept that is often misunderstood in companies that have had a little exposure to lean processes and have picked up the term.

Takt time is the beat at which we should make a product or component to be in synch with the needs of the customer. The customer may be an internal customer such as a downstream process, or it may be an external customer, a dealer or an end user. Takt is a German word for beat when the subject is music.  The baton used by a band or orchestra leader is called a taktstock.

Let us suppose that a customer of any type needs 900 units, widgets of some kind.  The factory works an 8-hour shift, but a half hour a day goes into breaks and other planned downtime, leaving 7.5 available hours.  Seven and a half hours times 60 minutes, times 60 seconds, equals 27,000 seconds of available time in a shift.  If we divide 27,000 seconds into 900 units, we find that our takt time is 30 seconds per unit.  To be perfectly synchronized with the customers requirements for a day, we need to produce one widget every 30 seconds and each operation in the process should take exactly 30 seconds.

No Right Way

Over twenty years ago, I was involved in a small group discussion in which my friend and colleague, Tom Lane, proposed three principles for consulting:

There is no right way.

The word is not the thing.

We make it all up.

I have not discussed these ideas with Tom in decades.  I believe that he has changed “the word is not the thing,” to “the concept is not the thing.”  I have recently bought his book, Perceptual Intelligence,  and started following his blog, Wake Up!

My comments here are not an attempt to present Tom’s ideas.  After that discussion, years ago, I have often reflected on those three principles and how they could be applied to consulting and to the process of changing work to bring out the best.  What follows is my own spin on the three statements.

Keeping it Simple

We often overcomplicate things at work.  Complicated machines become obstacles to getting the job done.

In one factory, a large, highly automatic machine spun nuts onto threaded nipples.  The operator’s job was mostly to catch defective nut-to-nipple assemblies as they came out of the machine and set them aside for later repair.  If practically all of the assemblies were defective, because the nut had not been spun on straight and had jammed onto the nipple, he shut down the machine, tried to make adjustments to it, and generally ended up calling maintenance.  While maintenance tinkered with the machine, the operator would sit at a workbench and use channel locks to removed jammed nuts from the nipples, so that both parts could be put back into the machine. 

Sometimes, there were so many flawed assemblies, additional workers would be brought to the area, given channel locks and put to work undoing the bad assemblies.

I worked with a team of workers and managers on an improvement project that made this problem go away. We purchased two nut drivers with sockets sized to the nuts in question.  The nut drivers were of the type that activate when you press down on the nut, and stop when you release the pressure.  We mounted these upside down, side-by-side, in the center of a small workbench.  We fashioned some brackets to hold them with the sockets flush with the tabletop, through holes in the center of the workbench.  We had a bin with nuts and a bin with nipples on the workbench. The operator would take two nuts and slide them into the sockets.  He would then take two nipples and briefly press them into the nuts in the sockets. This activated the drivers to spin the nuts onto the nipples.

Treating People As If They Were Robots

I have consulted to a number of plants with recently acquired robots.  Often the robots didn’t work very well.  In some cases the robots were doing work that made little sense.  In one case, the robot was taking a stamped part from a hanging line and putting it on a belt. It was so unreliable that a worker had to stand by to catch parts that were about to be dropped by the robot. Having the hanging line descend to just above the belt could have removed each part without a robot.

In a factory in Brazil, a robot cell had been installed to weld some parts together. A second cell was in the process of being installed.  Management was very proud of it’s new technology.  They had a five minute video of the robots in the dining room.  The bright orange robotic arms waved through the air and set forth a shower of sparks with each weld. The dramatic video played endlessly, for all lunch breaks on all shifts to see. 

Not a week had gone by since the robots were installed when they didn’t break down and required repair. No one in the plant could do the repair and the technicians who could do the repair were four hours away.  When they arrived it often took an entire shift to get the robots up and running again.