Lean Manufacturing

For Built-In Quality, Simple Is Best

By Jon Miller Updated on April 2nd, 2021

As part of our Lean manufacturing benchmarking trip we visited a bus manufacturing plant in Japan with a group of aerospace executives on February 27, 2006. We spent 6 hours observing their Lean manufacturing operation in action. We asked about their kaizen efforts and management philosophy for continuous improvement. Among the many things we learned was the “simple is best” approach to built-in quality. They way they guarantee quality through gemba kaizen (immediate, on-site improve) was quite ingenious.

In-Process Quality Gates

The production line had “Quality Gates” between each major process. Inspectors check the quality of the work performed by the workers. At first glance the number of inspections and checks made us ask, “Is this built-in quality?”

What was unique and smart about the whole operation was that the quality checkers were all highly experienced production employees. If they found a problem, they would call the worker over and point out the problem and how to fix it. The employee would then fix it and return back to their workstation.

The Quality Check as a Training Tool

In this case, the quality function was being used both as a training tool and a way to do kaizen. The employee would have a quality problem, improve their performance and receive a gift certificate as reward.

The management summarized the thinking behind their approach to quality kaizen as follows:

1. A person who knows the job, and who has done the job well is your best inspector because they know what aspects to watch out for.

2. It’s easier to take instruction from a person who has actually done the work than from an inspector who is not part of production. A person who has done the job before will be your best trainer.

Immediate Response, Reinforcement, and Reward

3. The employee who made the mistake leaves the work area to train and fix their mistake. The trainer shows them any short cuts or key points about the process that the employee may not yet fully understand.

4. By training the person immediately after the mistake is made, they understand the countermeasure needed and remember it most easily.

5. Once the worker shows improved performance based on the new standard they receive a reward. This is because people feel bad after being told they have produced poor quality. The quality gates process should not feel like a punishment.

This was a classic case where the company asked itself what results it wanted (quality kaizen, people involvement, built in quality) then found the simplest and most direct method get them there.

  1. ttganesh

    March 13, 2006 - 5:56 am


  2. Patrick Ng

    March 15, 2006 - 5:44 pm

    Hi Brad,
    I have read TPS recently, and I must say that your article motivates me. Thank you.
    Patrick Ng

  3. Harjono

    August 23, 2006 - 5:22 am

    good and very interesting to read.

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