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Six
Sigma
How
It Can Help Your Company
If
you’ve tried to find the magic bullet
to improve quality, you’ve probably survived
a few initiatives—TQM, ISO, OE, HACCP—learned
the seven habits of highly effective people,
studied critical success factors and read Quality
is Free. You may have preached quality to your
organization (or been preached to) for years.
Then there’s Six Sigma. How is it different?
Will profits increase? Why should you pay attention?
What
is Six Sigma?
Six
Sigma is a systematic process for eliminating
defects, a way to reach and maintain new levels
of quality. A company using the system understands
and satisfies customer needs. Six Sigma manages
with facts, data and statistics. The informal
Six Sigma motto is, “In God we trust,
all others must have data!”
The Greek letter
sigma is used in statistics to indicate standard
deviation—amount of variation—in
a set of data or a process. The term Six Sigma
refers to a level of 3.4 defects per million
opportunities: Nearly perfect.
The Sigma scale
is equivalent to the earthquake Richter scale;
every unit represents a 10-fold increase. Achieving
99% quality translates to 10,000 defects per
million and a sigma of 3.8; 99.9% quality means
1,000 defects per million and a sigma of 4.6;
99.99% quality yields 100 defects per million
for a sigma score of 5.2. Six Sigma represents
a quality level of perfection unachievable for
many industries.
Six Sigma performance,
and better, is attainable in many aspects of
the food industry. For example, if the defect
is the presence of live botulism bacteria in
canned goods, a performance level of 3.4 defects
per million cans would actually be much too
low; 3.4 defects per billion or per trillion
range is an expected goal.
Where E. coli
and Salmonella are concerned, fresh meat and
poultry can’t claim that level of food
safety. In these industries, Sigma values are
generally in the three to four range. Where
are your products? For every million customers
consuming one of your food products, how many
are dissatisfied?
The Five Steps
Six Sigma projects
are executed in five steps: Define, Measure,
Analyze, Improve and Control. During each of
these phases, data and the use of statistical
tools are critical. Many of the tools are not
new, yet work together and are applied with
a discipline that focuses on achieving and maintaining
changes in performance capabilities.
Easy
as Pie
Company X makes
pies, and at the end of every production line
is a QA station where “reject” pies
are pulled off the line. The rejection rate
averages 2%. No human inspector is perfect and
the definition of sub-quality pie is subjective.
Some pies pass inspection that contain what
some customers would call defects. When numbers
of customer complaints increase, the company
lectures the QA inspectors on rejecting more
defective pies. Yields drop and shift supervisors
are pressured to improve declining yields.
Six Sigma steps in
Define:
The Black Belt examines data, and learns that
customers have been reporting burnt crust. The
problem is re-stated—according to Six
Sigma—using data: “Burnt crust is
defined as a black spot greater than 1/2 inch
across on a pie. The 1.2% burnt pies cause losses
of $1.2 million dollars per year from rejected
pies and 30 monthly customer complaints.”
This is a Sigma performance of 3.8. A goal of
a minimum 70% decrease in defects is set.
Measure: Data is collected
on the prevalence of this defect: Area of the
crust on which burning occurs, type of filling,
type of crust, style of edge crimping, baking
line, shift, tin size and baking temperature
are evaluated. Collecting this detailed data
is difficult and time consuming, and requires
extra staff at the QA stations for two weeks.
Analyze: Statistical analysis
reveals that 70% of the burnt areas are located
at the edges. The low-shortening dough Type
A burns occur predominantly on pies with a particular
crimper style, while dough Type B is not sensitive
to crimp style. Analysis also reveals that 90%
of all burnt pies are produced on the outside
lanes of Line 2.
Improve: All low-shortening
pies use the crimper style that does not burn
as easily. The oven for Line 2 is tested and
found to be hotter at the outside lanes. Maintenance
adjusts the temperature balance. This not only
prevents burning, but saves electricity. Data
is collected showing that now 0.1% of pies are
rejected as burnt, yielding a Sigma score of
4.6, which saves $1.1 million dollars per year
and reduces customer complaints to two or three
per month.
Control: Manufacturing changes
all Type A dough pies to specify correct crimper
type. R&D puts testing of crimper style
and dough type into the standard testing regime
for new pie types.
Maintenance installs
multiple temperature sensors across oven widths
and Programmable Logical Controllers (PLCs)
to control variation.
Correcting problems, improving quality and improving
customer satisfaction doesn’t cost money.
These steps save money.
Six Sigma is
an implementation and improvement tool; if your
organization needs to progress, this may be
the right tool.
For implementation
of Six Sigma processes in the meat industry
contact us at CAT2.
Copyrighted material,
Food Quality magazine, www.foodquality.com.
Reprinted with permission.
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February
2004 • Special
Edition •
US Food Processors
