The Lean Toolbox: Where is the thinking cap?
By Bryan Lund:
The Lean toolbox is brimming with attractive tools and if you are like most Americans, you can't wait to get your hands on one of those shiny new gadgets and show it off to the neighbors. The problem with tools is that we get wrapped up in what they look like, not in the purpose of having the tool in the first place. Following is an example of where using a “lean tool” has gone bad. In this case, the 5 Why tool was put to work, and nothing happened, but was on display for the neighbors. Let's take a look at why good intentions went awry.
First, a quick glimpse of the picture: a group is in the middle of a kaizen event and someone says there is a chronic problem with a machine. A facilitator of the group says, “Let's use the 5 Why tool to solve this problem”, which the group proceeded to do. Following is the line of questioning and answers provided during the 5 Why session:
Problem: The parts carrier doesn't slide on the belt.
Why do the carriers not move along the belt?
The belt is caked with grime.
Why is there grime on the belt?
We are using silicone instead of light oil. Silicone builds up on the belt and attracts grime.
Why are we using silicone?
We need extra lubricant and silicone works for that. We normally wouldn't use silicone.
Why do we need extra lubricant?
There is a problem when the machine tries to screw the assemblies together.
Why is there a problem with screwing the parts together?
There is a problem with the threads, but we can't figure that out.
At this point, the group felt as if they had hit a dead end and threw the problem over the wall to engineering to solve. Fast forward 40 days.
This approach concerned me for several reasons. First, the group had a nice, stylish, flashy form created on the computer and dated 40 days prior to when we observed it on the machine. There was no status on the problem, and further discussion with the operators in the area yielded no other information. Another thing, the group literally stopped questioning at the fifth why. Problem solving sometimes requires multiples streams of questioning and certainly should never be limited to asking “why” only five times. Finally, it wasn't clear how a physical feature on the subassembly was causing grime to build up on the belt, thereby causing the carriers to stop on the belt. At first glance, it may be obvious that, “since the parts don't go together easily, we use more lubricant, which is transferred to the conveyor belt, causing grime to build up. This is basic 5S stuff!” Sadly, when we blindly using Lean tools we inadvertently reduce the credibility of a continuous improvement program.
About the author: Bryan Lund is a Lean Coordinator in the Global Lean Office for Energizer Battery Manufacturing. www.energizer.com. Bryan is also involved with the reintroduction of the WWII production improvement program, Training Within Industry, or, TWI. Many elements of TWI, notably Job Instruction Training, are fundamental to maintaining stability and improvements within the Toyota Production System. Learn more about TWI at our local SME #204 website: Training Within Industry