Zone Control 101 – Gemba tools for frontline supervisors, leadpeople and managers


If you would like some background perhaps you would find listening to my Previous podcast “Supervising and the war against waste” useful, that podcast briefly discussed the supervisors role in a lean environment and available tools and concepts to apply.

My Suggestions on Toyota’s “zone control”

Pascal Dennis in “Lean Production Simplified” describes Zone Control. “For example, a team leader’s zone was his or her immediate team and work area. The supplier and customer were the upstream and downstream team, respectively. This way of thinking compelled the development of redundant controls, which are the essence of reliability engineering”

Let’s look at zone control from the lenses of TPS’s operational priorities: Safety, Quality, Delivery, Cost’s in that order.

Safety 5S or 6S must be in place.

The objectives of 5S are

  • To organize the workplace
  • To make the workplace safe
  • To make the workplace more productive
  • To enable the workplace to support continuous flow
  • To put the operator in charge of his or her workplace
  • To create a better place to work

That means you have:

  • Sorted
  • Straightened
  • Shined
  • Standardized
  • Sustained through frequent audits

Creating a safer (the 6th S) environment

Your zone of control


Successive Inspection – standardized work is a prerequisite. The operator inspects and each incoming piece, (unacceptable pieces are returned to the upstream operation immediately), then the operator adds value with the standardized process and inspects the piece before passing it on to the downstream operation.

Poka Yoke – mistake proofing (gas pump nozzle/ gas tank opening sized so you cannot pump diesel into a gas engine) when properly accomplished achieves 100 percent inspection through mechanical or physical control


What is due now and what is next?
What visual signals are you using to identify problems?
Do you have everything you need to complete these jobs? If not, don’t start them!


ID & Elimination of waste a continuous process.
Is there a meaningful scoreboard posted for your zone?
How frequently is it updated?
Does everyone in the zone know the scoreboards meaning, purpose and how they can positively or negatively effect in real time?

More information on “zone control and related visual control”, both implicit and explicit can be found in:

“Lean Production Simplified” Pascal Dennis
“Workplace Management” Taiichi Ohno

“The Toyota Way” Jeffrey Liker
“Gemba Kaizen” Masaaki Imai
“A Study of the Toyota Production System” Shigeo Shingo

Ok, so now you have some of the basics of “zone control” but an overall “lean system” and standardization are prerequisites. Most of you know about value stream mapping and the steps for beginning your lean journey but how do we effectively implement standardization?

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