Join Steven Brown for an in-depth discussion in this video Why Six Sigma?, part of Lean Six Sigma Fundamentals.
- Albert Einstein once said that you can't solve a problem using the same kind of thinking that created the problem in the first place. That's a good quote to use here because Six Sigma is all about changing your thinking about both the problem and its solution. When someone mentions Six Sigma to me, the first thing they usually say is that Six Sigma was invented by Motorola. Six Sigma actually evolved over several years as a methodology, rather than something that was invented. No one sat down with the intention of inventing a Six Sigma methodology.
However, many people at Motorola were involved in gradually developing those methods. In the early 1980s, Motorola was struggling with some quality issues and productivity problems and had lost some significant memory chip business to Japanese competitors. Bob Galvin, Motorola's CEO at that time, issued some very tough quality goals for his company. And that is where the ideas behind Six Sigma began. The whole idea of Six Sigma is to provide reliable, consistent, dependable products to your customers.
The process focuses on three things: defects, variability, and the customer. It's important to understand how these three aspects work together. Six Sigma began as a way to reduce manufacturing defects to just a few parts per million. Now this was not a new concept. Japanese companies had been measuring their quality in parts per million since the 1960s, after they embraced Deming's quality concepts. Six Sigma drives the level of no more than 3.4 defects per million opportunities.
This is not 3.4 defects per million activities or process steps, but per million opportunities. There might be a million or more opportunities to make an error when building a house, for example. And each opportunity could result in a defect. So a house with only 3.4 defects upon completion, I think you will agree, is pretty close to perfect. The key to reducing defects to this level is controlling variability. All processes have some natural variability.
This is why Motorola felt that attaining zero defects, which was a very popular quality concept at that time, was just not realistic. Six Sigma is based on the belief that if variation can be reduced and held close to the middle of a product's specification limits, then there is less chance for defects to occur. Six Sigma in statistical terms means that the process variation can equal half of the design tolerance, allowing the mean to shift as much as 1.5 standard deviations from the target.
In non-statistical terms, this means that your manufacturing processes are very much in control and your variability is very small. Motorola chose this range because they found that their typical processes naturally drifted this much. Again, all processes have some natural variability, and Motorola wanted to be able to control their processes within that natural range. Now, we have talked about defects and variability, so where does the customer come in? Six Sigma projects have a very strong focus on results.
They also provide a structure for project management through their formal training and certification of green belt and black belt and master black belt experts. Each having a higher level of knowledge and skills. With that focus on the customer, Six Sigma projects strive for more of a breakthrough approach to process improvement rather than a gradual approach. As such, Six Sigma can be considered as a very important and more structured component of a company's continuous improvement philosophy and strategy.
Six Sigma has evolved from this statistics-based management of manufacturing defects into a sound business strategy to drive process improvement across the entire organization and its supply chain. You can apply these methods to reduce variability in your transportation department to help improve on-time delivery to your customers. Working closely with suppliers, Six Sigma can help reduce quality issues with materials coming into your factory. Clearly, Six Sigma is designed to guide quality efforts in every part of your business.
Most people today do not work in a Six Sigma company, but the foundation for building a solid program already exists in most companies. It's called Statistical Process Control, the acceptable tolerance within each specification that allows that process to be "in control" and produce quality output. That's the place to start.
Steven outlines the process stages in Six Sigma (define, measure, analyze, improve, and control), along with the Lean toolkit: the 5s principles, kanban (scheduling), downtime, poka-yoke (error proofing), and kaizen (continuous improvement). He also explains how leadership works within Lean Six Sigma, the principles of project execution, and how Lean Six Sigma is applied to the service sector and supply chain management. Make sure to watch the "Next steps" video at the end of the course for further resources.
- Why Lean Six Sigma?
- Understanding the five steps of Six Sigma
- Understanding the 5 Ss of Lean
- Leading a Lean Six Sigma project
- Controlling a Lean Six Sigma project
- Using Lean Six Sigma for services and supply chain management