2. The normal distribution is a descriptive model
that describes real world situations.
It is defined as a continuous frequency distribution of
infinite range (can take any values not just integers as
in the case of binomial and Poisson distribution).
This is the most important probability distribution in
statistics and important tool in analysis of
epidemiological data and management science.
What is Normal(Gaussian) Distribution?
3. It links frequency distribution to probability
distribution.
Has a Bell Shape Curve and is Symmetric.
It is Symmetric around the mean:
Two halves of the curve are the same (mirror images).
Characteristics of Normal
Distribution
4. The mean ± 1 standard deviation covers 66.7%
of the area under the curve.
The mean ± 2 standard deviation covers 95% of
the area under the curve.
The mean ± 3 standard deviation covers 99.7%
of the area under the curve.
Distinguishing Features
33.35%
13.6%
2.2%
0.15%
µ 1 2 3-1-2-3
Diagram of Normal Distribution Curve (z distribution)
5. It’s application goes beyond describing distributions.
It is used by researchers and modelers.
The major use of normal distribution is the role it
plays in statistical inference.
The z score along with the t –score, chi-square and F-
statistics is important in hypothesis testing.
It helps managers/management make decisions.
Application/Uses of Normal
Distribution
6. Quality management program developed by
Motorola in the 1980s.
Management philosophy focused on business process
improvements to:
o Eliminate waste, rework, and mistakes.
o Increase customer satisfaction.
o Increase profitability and competitiveness.
Statistical measure to objectively evaluate processes.
GOAL: Reach Six Sigma Quality
Six Sigma Defined:
8. Customer Satisfaction Improvement Plan
IMPROVE
CUSTOMER
SATISFACTION
Improve
product
quality
Make prices
more
competitive
Improve
customer
support
Increase quality
control testing
Invest in more
usability testing
Use higher quality
materials
Increase market
research budget
Work with retailers
to increase volume
and lower prices
Require results-
oriented training
Increase level of
experience required
for hiring
Lower cost of fee-
based support
Institute mentoring
program
Add support options,
such as Internet
9. Do you run an efficient business?
Consider this:
If your company's processes are working at 99%
efficiency and you receive 300,000 orders a month,
you'll face 3,000 failed orders every month.
If your company's processes are working at Six Sigma
efficiency, those 300,000 orders will result in only 1
failed order every month.
Use Six Sigma to measure and improve
processes
10. Six Sigma is an approach to quality control that focuses on
measuring and improving the processes that your business
uses to create your product. Every aspect of your business
that is concerned with cost, timeliness, or quality of results
can benefit from the Six Sigma approach. Six Sigma helps
you understand what aspects of your products are most
important to your customers; where your processes are
inconsistent; and what improvements will give you the
greatest financial return on your effort.
Use these solutions to put Six Sigma
methodology to work for your business.
