Monday, January 13, 2020

Poka-Yoke – Preventing Inadvertent Errors

By Al Norval (bio)

We talk a lot about the House of Lean with its foundation of Standards & Stability and the two pillars of Just In Time and Jidoka supporting a roof of Customer and Strategic Direction which together encompass engaged Team Members continually solving problems.

All of this makes sense but what is this Japanese word – Jidoka?

It’s built in quality at the source. Rather than try to inspect and test quality in by looking for defects on finished product, a losing cause at best, lean organizations build in quality at the actual value added operation. That way defects can be caught early and they don’t have to reply as heavily on final inspection testing.

The big advantage to Jidoka is that by catching defects early in the process, they are closer to the actual process conditions that caused the defect and therefore closer to root cause. They can launch problem solving faster with a higher chance of getting to root cause since the process conditions wouldn’t have changed as much.

Jidoka has four parts:
  • Detecting defects
  • Alerting or signaling a problem
  • Immediate response - temporary countermeasures to get running again
  • Root cause problem solving and countermeasures to prevent the occurrence of the defect.

This is where Poka-Yoke comes in. It’s about the final step in Jidoka of preventing the re-occurrence of the defect. Lean organizations realize that errors are inevitable. Human beings make errors that cause defects. By eliminating the possibility of the error being made, defects could be eliminated. Poka-Yoke is used to prevent these errors being made. Translated it means “Preventing inadvertent mistakes” since it’s believed people don’t make mistakes on purpose. This is consistent with the lean principle of “Respect for People”

The best Poka-Yoke devices are physical devices that eliminate the possibility of an error occurring. Weaker Poka-Yoke countermeasures would be signs and warning systems but these could be overridden and the error could still occur.

Organizations are always looking for ways to get employees involved and having teams develop Poka-Yoke devices that prevent errors from being made is a great way to do this. It’s a win-win. Employees are engaged in problem solving, quality gets better for customers.

For more on Poka-Yoke, download the free Lean Pathways “LEAN MANIFESTO



In case you missed our last few blogs... please feel free to have another look…

Making the Invisible Visible in Design Projects
Two Pillars of the Lean Business System
Why Do We Learn More from What Did Not Work?
Failure is a Requirement for Innovation

Monday, December 30, 2019

Making the Invisible Visible in Design Projects

By Al Norval (bio)

Have you ever walked through a large design center and wondered what the heck was happening there?

If so, you wouldn’t be the first one to do so. What do we see? Lots of people working at computers in their cubicles.

What’s the current condition?

Is everything OK?

Are we meeting the needs of our customers?

Is anyone having any problems?

This is not to imply that these people aren’t working hard, it’s just difficult to tell what’s going on.

Why is it like this? Because the work is invisible! It’s not like a manufacturing process where we can see the flow of materials going through the factory. We can’t see the flow of a project. The key then becomes making the invisible work visible so we can see the flow of work, the status of the project and most importantly see any problems that are occurring. All projects have problems, all designs have problems, in fact all organizations have problems. What separates the great ones from everyone else is their understanding of this and their ability to surface problems and solve them.

How do we make the work visible?

  • Use simple visuals to track progress. Red/ green, hand drawn Gant charts or a simple timeline with 5 or 6 key milestones.
  • Keep a scorecard with a few key metrics – meeting Customer Needs, on time, on budget
  • Make work assignments visible by showing the projects assigned to each person on a card.
  • Stacking cards allows you to assess whether they are at capacity or not.
  • Unassigned projects or tasks can go into a queue which can then be made visible.
  • Do a FMEA at the start of a project and for the top 3-5 problems, put in a standard countermeasures. Both potential problems and countermeasures are made visible.
  • Do a weekly check of project status where people check for on or off track.
  • Make things Yes/ No, or binary which forces problems to the surface.
  • For problems, make them visible as well, keep an action log and make visible who, what, when and status.

People say “why do all this it’s in the computer” but that doesn’t make it visible to all. When it’s in the computer it’s only visible if people go look for it which they usually don’t do.

Key is that when we all see together, we understand together and take action together.

Sounds simple right?

Try it out and let me know how it works



In case you missed our last few blogs... please feel free to have another look…

Two Pillars of the Lean Business System
Why Do We Learn More from What Did Not Work?
Failure is a Requirement for Innovation
KAIZEN – Small Changes vs. Monster Projects

Monday, December 16, 2019

Two Pillars of the Lean Business System

By Pascal Dennis (bio)

Continuous Improvement and Respect for People - big ideas that deserve to be capital letters!

These reflect the infinite finesse of the Lean Business System.

They are yin & yang, masculine & feminine, mind & heart.

Each contains the other, as in the famous yin/yang image.

Continuous improvement is largely, though not entirely, an affair of the 'rational mind', which some people call the 'Left Brain'.

We need to know the fundamentals, including Value/Waste, 5 S, Visual Management, Standardized Work & the like.

We need enough problem solving 'reps' so that our core katas become part of our muscle memory.

Respect for People is largely, though, again, not entirely, an affair of the 'heart, which some people call the 'Limbic Brain'.

Respect for People requires empathy, and a solid grounding in core values.

Our readers will know, by now, that for me, this means the Cardinal Virtues:


These figure strongly in my book, Reflections of a Business Nomad.

By the way, my friend and colleague, Dr. Reldan Nadler, has written persuasively about the importance of Emotional Intelligence in leaders.

I recommend his books warmly.

Best regards,


Why Do We Learn More from What Did Not Work?
Failure is a Requirement for Innovation
KAIZEN – Small Changes vs. Monster Projects
Is Inventory a waste or a cover-up of deeper waste?