We continue with the six part series covering the five principles of lean improvement. Thus far, I have discussed creating flow and what that means to a lean organization. Secondly discussed the second principle known as pull. Today's topic is developing a system that is capable of delivering zero defects.
Of all the lean principles, perhaps none is more important than eliminating defects. Human beings, by our design, are prone to make errors. A defect is an error that reaches the customer. Ideally, we seek to be error free, but we can live with a system that prevents any error from reaching our end customer.
Defects in their minor form, only serve as a nuisance. The ketchup pack left out of your order of fries, or the garment your find without a price tag when you get in a line with many waiting customers behind you. A worse from of defect is that which requires a lot of rework adding cost and time to your products and services while eating at the staff doing the work.
In the extreme, defects can cost people their lives. The sign that falls of the building, the wrong medicine given to a patient, or the truck accident leading to a gas leak or fire.
A lean organization seeks to design systems that prevent defects. Preventing defects is not as easy as a memo saying no more defects. Process and culture must be changed to create a world class organization that approaches defect free processes. To get started simply start by capturing and reporting on errors. In many organizations I work with, the staff and the management have no idea of the quantity and source of defects. You can't fix what you can't see.
There are a host of lean tools designed to move processes toward zero defects. The short list includes the following:
- successive operator checks
- mistake proofing (hard and soft)
- closed loop corrective actions
- standard work
- recipe cards
- 5 Why's
- quality at the source
- root cause analysis
- A4 problem solving
- cause and effect diagram
- 7 Quality Tools
The key point, regardless of the tools or concepts used, is that for a system to reach its potential, you must develop a way for the work to be done right as it progresses through the value stream. Thinking zero defects and then applying zero defect approaches is a great way to start.
Think about a defect for a second. Think about the wastes that is causes: at a minimum inventory, waiting, and rework. Defects also impact people in a negative way and as such, are disrespectful to the worker. Defects also increase cost since they take time, space, and resources but fail to deliver value to a customer.
Your role is to design process that are defect free.
President, Breakthrough Horizons Ltd