Lean Manufacturing Requires Responsive and Reliable Maintenance

Lean operations require maintenance that is responsive and reliable.  When we have isolated operations that are adding value to pieces in a batch that eventually gets passed on to another operation, one machine going down does not present itself as a critical event.

If we have many operations organized in a cell and one piece of equipment breaks down, the entire cell goes down.  We require equipment that does not go down very often – ideally not at all – and when it does go down we need to get it up and running as quickly as possible.  This imposes requirements on the maintenance system. The maintenance system is not limited to the maintenance function.  The system includes standard procedures that are followed by the operators and equipment that does not breakdown and/or can be repaired quickly.

A good way to begin to improve the maintenance system starts with a workshop focused on a single piece of equipment that is or will be critical to a lean, one-piece-at-a-time operation.  The workshop team goes through a process of detailing the machine.

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.

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.