Lean and Six Sigma are buzz-words we hear in business all of the time. Lean tends to be used for shorter, less complex problems which are often time driven and focused on eliminating wasteful steps and practices. Six Sigma is a bigger more analytical approach – often quality driven – it tends to have a statistical approach focusing on optimizing the important steps and reducing defects.
Some argue Lean moves the mean, Six Sigma moves the variance. But they are often used together and should not be viewed as having different objectives. Six Sigma training might be specialized to a specific division, but everyone in the organization should be trained in Lean.
Comparing Lean and Six Sigma
Essentially, Six Sigma and Lean systems have the same goal. They both seek to eliminate waste and create the most efficient system possible, but they take different approaches toward achieving this goal. In simplest terms, the main difference between Lean and Six Sigma is that they identify the root cause of waste differently.
Lean practitioners believe that waste comes from unnecessary steps in the production process that do not add value to the finished product, while Six Sigma proponents assert that waste results from variation within the process.
Of course, there is truth in both of these assessments, which is why both Lean and Six Sigma methodologies have been so successful in improving overall business performance in a variety of fields. In fact, these two disciplines have proven to be especially successful when working in tandem – hence the creation of Lean Six Sigma.
What is Good Enough?
|99% Good (3.8 Sigma)||99.99966% Good (6 Sigma)|
|20,000 lost articles of mail per hour (based on 2,000,000/hr)||7 articles lost per hour|
|Unsafe drinking water for almost 15 minutes each day||1 unsafe minute every 7 months|
|5,000 incorrect surgical operations per week||1.7 incorrect operations per week|
|2 short or long landings daily at an airport with 200 flights/day||1 short or long landing every 5 years|
|2,000,000 wrong drug prescriptions each year||680 wrong prescriptions per year|
|No electricity for almost 7 hours each month||1 hour without electricity every 34 years|
|$287,000,000 lost every year (based upon a $28.7 billion budget)||$975.80 lost every year|
|2,390,000 tax returns incorrectly processed every year||813 tax returns process incorrectly|