Page 32 - Design for Six Sigma for Service (Six SIGMA Operational Methods)

14 Chapter One

Materials
Procedures
Methods
Products
Information (including
specifications)
Services
People
Process
Skills
Information
Knowledge
Training
Paperwork
Plant/equipment
Inputs Outputs
Figure 1.5 A Diagram of a Process (Oakland, 1994)

means that the product has to be designed perfectly so it captures maximum
customer value; the product should deliver superior performance to its
customers. Do things right means that a product or a process should be able
to perform consistently and defect-free.

Actually, the name Six Sigma came from statistical terminology. Sigma, or
s, means “standard deviation.” For a normal distribution, the probability of
falling within a ±6 sigma range around the mean is 0.9999966. In a pro-
duction process, the Six Sigma standard means that the process will produce
defectives at the rate of 3.4 defects per million units. Clearly Six Sigma
indicates a degree of extremely high consistency and extremely low vari-
ability. In statistical terms, the purpose of Six Sigma is to reduce variation
to achieve very small standard deviations.

A perfect product or process is one that will do the right things, and do
things right. A perfect example is an Olympic gymnast. If an athlete wants
to win a gold medal, he or she must first do right things; that is, he or she
must be able to design and execute absolutely world-class routines (10.0-point
performance). The routine has to beat those of all competitors, and impress
the judges and audience. A 9.0-point routine, no matter how flawless and
consistent, will not do the job. Secondly, the athlete has to do things right
every time. If the athlete can sometimes do an excellent job, but sometimes
does a poor job, he or she will not be able to win the gold medal.