Quality at the Source – How it Works

by James P. Tate on December 5, 2011

Quality at the Source (QatS) is one of the lean building blocks of Lean Manufacturing Concepts.  It is one of the most misunderstood and overlooked of the 14 building blocks.  However, it is a powerful, stand-alone set of skills that can produce significant results even if not used in a complete lean implementation.

Quality at the Source is predicated on the idea that you don’t want to produce bad product at any work center.  Although this idea sounds obvious, we all know of situations where bad product is manufactured at a work center and the problem is either swept under the rug, or ignored with a volume of production.  The solution to this situation can be surprisingly simple.  If we want to improve the product quality we can employ the techniques of Quality at the Source.

Quality at Source is composed of five key factors: Standardized Work; Self-Checks; Successive Checks; Visual Management and Mistake Proofing and Continuous Improvement.  The symbol of Quality at the Source is the Andon light.  This light at a work station is turned on when the quality drops to a certain level or (even better, a bad product is made).  Work stops at the work center and a team of workers and engineers rushes to the light and begins to address the problem to eliminate the cause of the bad production.  There are many production managers who would have apoplexy if a worker stopped production because of a bad product.  After all, production quotas and deadlines must be met.  We can’t stop the wheels because of a single bad product!

However, let’s understand the five key factors of Quality at the Source:

Standardized Work:  To eliminate variation in production quality, first make sure everyone is making the product in the same manner.  Document the work methods, materials, tools, machinery settings and training of each worker and work station.  Focus on the methods, not on the output.  If the methods are consistent, the output will be consistent.

Self Checks: Design simple gauges to measure the key parameters of the production output at the work station.  Enable the workers to measure the output themselves and if it is not to spec, raise the flag for help.

Successive Checks: Make regular checks of the output to ensure the work quality is consistent.  Then have the next downstream work station measure the input coming to it to see if everything is to spec to continue the production stream.

Visual Management and Mistake proofing:  This is where the Andon light come in.  But you don’t necessarily need these lights.  You only need a means of signaling that production quality is not right.  If a drop in production quality is detected, a team of engineers and workers must immediately go to the work center to analyze the problem and implement corrective action.  This corrective action is not something done once a week or at convenient intervals, the problem is addressed immediately when it is discovered.  Why wait and continue to waste time and material on bad production?

Mistake proofing related to analysis of the causes of the poor quality.  Using root cause analysis, and other quality analysis tools you can determine the real cause of the problem, and make real changes that affect a permanent solution to the production quality.  If a design has to be changed or a machine setting adjusted, there is no justification for waiting.  Make the proper change and start back on production.

Continuous Improvement:  This is probably the hardest technique for management to understand.  It incorporates a change in management style.  As you introduce improvements to the process and quality improves, you can’t rest on your laurels.  You must have a system to continuously evaluate the quality and make further improvements.  In reality, you are always seeing production stoppages, but they will be of shorter duration than you saw at the start of this improvement process.  You will see a constant improvement is quality and output.

Quality at the Source can be a powerful tool, even without the Andon lights, and should not be overlooked because you can’t stop to fix problems.  Don’t let deadlines get in the way.  After all, would you continue to drive down the road on a flat tire and destroy the tire and rim because you don’t have time to change the tire?

Next Time: How to implement this building block

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