Today’s Guest Blog Author: Kris Chapman is the Vision Lean Manager at Trilogiq USA. Kris has 15 years experience in helping manufacturing facilities implement Lean Manufacturing principles.
The last of the seven wastes is Defects. This is probably the most recognized waste, and an issue many of us have had to deal with and work through to keep things rolling and rework the issue. It is described as something made that does not meet the customer’s requirements. Defects have been around for as long as manufacturing has, and it can be the result of human or machine error, design issues, or poor quality material. Having defects contributes to the other six wastes and can be challenging to resolve due to the quickly changing environments that most of us work in.
The result of defects is reworking or scraping the product, and that increases the steps in the process. This adds cost and time to document and contain the issue.
A good picture that is used in many Lean examples is an iceberg. The image above illustrates that what is causing the defect is often hiding below the surface and needs thorough investigation. Only a few issues are visible on the surface, but many more can be causing defects that are not so easily identified.
By not making the product correct the first time, you will experience the following:
- Added costs
- Interrupted schedules,
- Consumed resources,
- Added paperwork,
- And reduction in customer confidence.
- All of the above side effects negatively affect an organization’s bottom line.
Many methods are available to help fix or catch defects. A popular in-process system is a Poka-yoke. An example of a poke yoke can be a pick to light system, a photo verification system, or a go/no go system. All of these are used to prevent a defect from occurring. Poka-yokes can be costly, but if you have a chronic issue with defects it may justify the investment needed. Other tools can be used such as Six Sigma or Red X, which are geared toward finding the root cause of an issue and predicting the defect, both leading to discovering what’s hidden under the surface.
Thank you for reading our Tim Wood blog series. We encourage you to conduct regular Gemba walks to identify wastes and understand why it is important to address the seven wastes.