Why #Lean Fails in Job Shops!

Article written by Greg Lane & Chet Marchwinski

 

Like many job shop owners, Greg Lane struggled with implementing lean principles. The problem was that the experiences and books that he, like other job-shop managers, had been exposed to were based on repetitive manufacturing. Job shops with their high-mix, low-volume product lineup present a challenge to lean thinkers — but not an insurmountable one.

“People get turned off too quickly, for example, because they don’t see the direct application of a tool and they don’t go back to what is the principle” behind the tool, said Lane, who learned lean management from Toyota Production System experts at the automaker’s plants in Japan. “When I bought my own job shop and tried to apply lean through the school of hard knocks, I found that if I went back to the lean principles enough, I was able to successfully implement the concepts.”

For example, job shop management often struggles with the lean concept of takt time, sometimes called the “heartbeat” of a lean production system because it paces production to demand. Takt time is calculated by dividing available production time by customer demand.

“In a job shop, we generally can’t figure that out,” said Lane.  “I only know customer demand for the current order. So I’m not able to plug numbers into the equation.” But the concept of matching output to customer demand still applies.

“Time available becomes whatever time you need on the machine,” he explained. “And every time we quote a job to a customer and that customer gives us a purchase order, we have a market acceptable rate to plan and measure against, and that’s our takt time. That’s our relationship to the customer.”

Lane discusses other important points about implementing lean in a job shop, including:

• What’s the same and what’s different about implementing lean principles in repetitive versus non-repetitive manufacturing
• The main reasons why lean transformations fail in high-mix, low-volume shops
• How lean management helps to accurately calculate margins, a challenge in high-mix, low-volume product lines.
• How to know where to focus your time for problem solving and other leadership activities when there are hundreds or thousands of SKUs to manage