Six Sigma in the dock

So what is six sigma?

Unfortunately, there is no single, universally accepted definition of 'six sigma'.
It means different thing to different people.

Wikipedia defines it as - A business management strategy.
"It was originally developed by Motorola and today enjoys widespread application in many sectors of industry. It seeks to identify and remove the causes of defects and errors in manufacturing and business processes. It uses a set of quality management methods, including statistical methods, and creates a special infrastructure of people within the organization ("Black Belts" etc.) who are experts in these methods. Each Six Sigma project carried out within organization follows a defined sequence of steps and has quantified financial targets (cost reduction or profit increase)."

Quite a mouthful.

In simple terms

• Sigma (Σ) is a letter in the Greek alphabet.
• It is the term used by statisticians to measure the likely-hood that a process will produce a defect
• The chances of producing a defect take account of the number of 'opportunities' for a process to go wrong
• Processes can be given a rating - 1Σ, 2Σ, 3Σ and so on up to 6Σ and beyond
• If, for example - in every 'million opportunities' for a process to go wrong / produce a defect:-

- 697,672 defective parts are produced, then the process is rated as 1 Sigma (1Σ)
- 308,770 defects = 2Σ
- 66,811 defects = 3Σ

- 6,210 defects = 4Σ

- 233 defects = 5Σ
- 3.4 defects = 6Σ

• People can be formally trained in the various six sigma techniques for improving processes - and 'grades' are used to signify their level of expertise - Yellow Belt, Green Belt, Black Belt and Master Black Belt. The term 'belt' has simply been taken from martial arts.

That's it in very simple terms - but anyone who delves into this 'black art' will find that it is littered with complexities and has its own language.

If a full understanding of six sigma is required then the Wikipedia website contains chapter and verse.

So... is Six Sigma value for money?
Are the claims fact or fiction?
Let's put 'Six Sigma the dock'

The case for and against Six Sigma

The prosecution's evidence is summarised:

• A very poor success rate in many organisations
• Creates elitists and can be divisive
• Black belts need to be 'full-time' - and can slow down initiatives and cause loss of competitive edge
• Evidence that it is just a 'fad' - following industry leaders
• Does not suit all companies - and can cause cultural problems
• Overly complex - and large investment in training tools and techniques, much of which are never used
• Training in process improvement tools is not sufficient
• Focuses on cost rather than value
• 3.4 defective parts per million - may be unobtainable
• Starts with 'define' rather than 'check the system'
• Bad news and failures are never publicised

The case for the defence is:-

• Provides common goals
• Relentless pursuit of excellence
• Emphasis on flawless execution
• Tough measurement system that makes leaders responsible
• Makes a competitive difference
• Combines problem solving and innovation
• Creates a business culture that motivates teams
• Most Fortune 500 companies in the US using it - to some extent
• Many examples of it saving money
• Scaleable

The verdict

The jury is still out.

Our recommendation

Make sure you have a good understanding of what 'Six Sigma' is all about before making a decision on whether or not to invest in it.
Then, and only then, decide which part or parts of it are going to add real value to your business.