What is Lean Six Sigma?

Lean Six Sigma is a business improvement methodology which combines (as the name implies) tools from both Lean Enterprise (Manufacturing) and Six Sigma.  Lean eliminates the waste in your processes, while Six Sigma ensures quality through the elimination of variation in your processes and also provides a structured data driven structure to solve problems and implement sustainable change into your business.  We believe therefore that the best approach for any business is to use Lean Six Sigma rather than one or the other.  The benefits from taking this approach are proven to out way taking only one approach at a time.   To understand Lean Six Sigma let us first explain the two methodologies. 

Six Sigma is a set of practices originally developed by Motorola to systematically improve processes by eliminating defects.  A defect is defined as nonconformity of a product or service to its specifications.  In other words every time you do an activity you get exactly the same outcome (result), the same quality.  For example if I fill in a form or take an order or solve a customer issue or make a part no matter who does it the output is the same.

Top companies all over the world including Motorola have made Six Sigma a way of life for their business. This however requires commitment to the approach from top management down.  If this is achieve then implementation and acceptance is easier and leads to massive savings.  Motorola have made $17b savings up to 2006 using the approach.  It ensures that everyone focuses on reducing variation in every aspect of the business from filling in forms to making a part.  All activities in a business of any kind can be measured, analyzed, improved and controlled and thus using some simple tools can give a reduction in variation leading to improved quality and costs. 

Why do we want a reduction in the variation we obtain from any activity in our business?  When we have the same output from a process or activity we know what we are going to get which makes the next step in the process easier and quicker to complete.  It reduces the amount of time wasted completing a task and it means that the quality of a part or process step is higher reducing the need to rework or redo the activity.  The simplest analogy is to think of golf and putting into the hole.  If every time you took a putt you got the ball into the hole think how good that process would be, now think how good your putting is.  In business if every time a part was made it was identical in every way to how it was meant to be - shape, form, look, feel etc that would mean we would have no quality issues.  If we were completing a form and every time every field was correct, easy to read, all data correct, all numbers correct and it was the right form think how quickly things would be done.  Well that is what Six Sigma is all about reducing the variation in everything you do. 

The term "Six Sigma" refers to the ability of activities or processes to produce output within specification. In particular, processes that operate with Six Sigma quality produce at defect levels below 3.4 defects per (one) million opportunities (DMO).  Six Sigma's implicit goal is to improve all processes to that level of quality or better.  That would mean that every time you did something one million times you would only make a mistake 3.4 times. 

To achieve these improvements in variation and therefore quality improvements and cost reduction Six Sigma uses an approach to solve problems (sources of variation) which is a standard methodology which everyone must use when solving problems regardless of size.   DMAIC which was inspired by Deming's Plan-Do-Check-Act cycle is a sequence which if followed will ensure that not only will the root causes be identified but the best solution will be found then implemented into the organisation permanently rather than for a short period before it goes back to how it was.  If you are designing a new process or product then the methodology used would be DMADV.

DMAIC

Basic methodology consists of the following five steps: