By Kevin Meyer
A couple weeks ago I re-read Michael Balle's excellent business novel, The Lean Manager. One concept that has been nagging at me is the idea of flexibility as a form of waste. Most of us in the manufacturing environment work hard to cross train so that operators can flow between processes and stations, usually in an attempt to reduce batch size and improve general knowledge.
The lean guru in Michael's book looks at it from a different perspective, when mentoring his plant manager on how to create basic stability through stable part families that go through stable processes and dedicated equipment.
"Next you're going to tell me that the operators should always be at the same station, working on the same parts to gain as much familiarity as they can on the parts."
"And how is that surprising? Do you do any sports?"
"Me?" he laughed. "No, it is against my religion. But my wife trains competition jumpers. Why?"
"Does she? So here's a big puzzle. If one rider is trying to win a specific event, should he train every day on a different horse on a different type of course in order to learn riding 'in general' or would he —"
"Ride the same horse on the same course every day to know the animal's reactions and the terrain by heart. You're right, it's pretty obvious. But we can't keep operators at the same stations all the time."
"Well, any one station doesn't operate continuously."
"Because… ok, I get it. We're not producing at the customer's rhythm, so we're creating inventory while moving people around. It's dumb."
"The 'flexibility' you have in mind is not true flexibility. It's keeping for yourself the latitude of moving people around if one station is down, so you can maintain your efficiencies by working on something else while you take your sweet time fixing the equipment. And so what you get is 'flexibility' for your production manager, not for your product flows. In effect, it's a license to accept waste." [pages 92-93]
This idea startled me at first. It took a second read to realize he's not suggesting eliminating cross training, but instead having dedicated people and processes and equipment. The same operator, or operators, work on smaller and smaller batches at the takt of demand across smaller intervals of time, which may not fill a full day. In those cases a change is made to different products and even processes, requiring people trained in multiple operations, but the same people still work on the same parts.
Note the use of "Why?" and how the CEO in this case is teaching his plant manager by challenging the process and developing solutions… at the gemba. This lean leadership model is pervasive throughout the story, and a reason why I highly recommend the book.