Seven Basic Quality tools documents
Definition of Quality Management -- it is a method for ensuring that all the activities necessary to design, develop and implement a product or service are effective and efficient with respect to the system and its performance. It is also a principle set by the company to endure the continuous advocacy of quality services and products, or the further improvement of it.
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Andy Labrum
Opmgmt 345
Prof. Dr. Foster
11/18/2002
Defect
Parts Per Million (DPPM)
Original text on www.freequality.org
Quality management is more important
today than it ever has been in production operations. More and more producers and customers are
demanding greater reliability in the products they create and the products they
buy. An increase in demand for greater reliability in the production fields
entails an increase in reliability on the assembly lines. Many companies determine the reliability of
their product(s) using a simple yet effective concept known as “defect parts
per million.” Defect parts per million
(DPPM) can be defined as the average number of defects in an average production
run multiplied by one million. DPPM is a
statistic that is given as an estimation of the entire production load.
DPPM = (# defects/# opportunities) x
1,000,000
In order to use the concept known as
DPPM effectively, one must understand why he/she needs to use the concept. DPPM is a concept that originated to help
stakeholders of organizations compete in the highly
competitive money market. DPPM is a
significant tool if it is used to improve an
organizations current output standards.
Generally an organization will project where
they would like their DPPM to be in x number of days.
The model known as DPPM can be used
in a variety of different industries.
For example, DPPM has been used to determine the reliability of
information that the Internal Revenue Service provides to tax payers. It has also been used to determine the
reliability of airlines in terms of the amount of deaths that occur in that
industry (the lowest DPPM known in any major industry: .52 DPPM). DPPM is essentially a statistical tool that
can be used by several different groups of personnel within an
organization. Accountants, financial
consultants, engineers, managers, and production operators are just a few of
the many groups within an organization that can use DPPM as a beneficial
tool.
DPPM can be measured at various
stages within the production process but the standard measurement point is at
the finish of the assembly process. The
finish of the assembly process is generally after the product has been packaged
and shipped. With this in mind there are
several conditions that could negatively affect the DPPM aside from the actual
production and/or assembly of the product.
They include:
Ø
Erroneous
packaging
Ø
Products
being damaged due to deficient packaging
Ø
Misidentified
parts and/or materials being packaged
Ø
Incorrect
material was shipped
Ø
Declared
product size was not in container to be shipped
Recently, a concept known as six sigma (6s)
has become popular in the electronics industry.
Six sigma refers to variance or the amount of
standard deviations a production run is away from being perfect (the mean
projection). Six sigma
is essentially having only .002 parts defective out of one million produced or
a 99.9999998 percent chance that the item being produced will be
defect-free. These rates are extremely
exceptional and may not appear possible to implement. There is a production consulting concept
called ‘Six Sigma’ that actually equates to 3.4 defects per million, not .002
parts per million as a true 6s would equate to. ‘Six Sigma’ assumes
that the mean can move 1.5 standard deviations to the left or the right,
leaving a standard deviation of 4.5s. A standard deviation of 4.5s from the mean is 3.4 parts per
million. Motorola, for example,
established a goal of 3.4 DPPM.
Improving production reliability
standards is essential to driving a business successfully into the future. DPPM is a critical tool implemented by
today’s most highly competitive businesses.
There
are several websites that offer more information on the DPPM and the six sigma
concepts discussed above. They include:
References
Internet
websites:
http://mu.motorola.com/sixsigma.shtml
www.all-six-sigma.com/SixSigmaName.htm
www.imu.ac.uk/lis/imgtserv/tools/sixsigma.htm
www.isixsigma.com
www.smartgroup.org/pdf/NepSem/BobWillisppm.pdf
Text:
Russell, Roberta S. and Bernard W.
Taylor, Operations Management. Upper
Saddle
River: Prentice Hall, 2001.