RESEARCH
27
Six Sigma has statistical and from the center line. In other goal could be met when
business perspectives and its words, the range of the the sigma level is 6. For
applications are improved lower or upper limit defect instance, at Sigma level
by Six Sigma Academy.
is ±6 sigma from the mean /3/, 93.3% of items' quality
The
large
number
of which is the simple average are acceptable and free
researches have been done of data.
of defects where 66,80 0
in its application in different Six Sigma aims to improve defects occur per million
industries.
the
potential the quality near perfection opportunities (DPMO) as
area
for
performance which means 3.4 defects per showninFig(2),butimproving
improvement in terms of Six million opportunities (DPMO), the performance to 5 sigma
Sigma strategy and numbers
of case studies are reviewed
to evaluate the flexibility of
the principles in complex
industriessuchasconstruction
industry.
Construction
work has fragmented and
project-oriented
work
processes compared to the
manufacturing industry. So,
the evaluation of Six Sigma
within construction context
becomes
an
interesting
research
to
figure
out
whether Six Sigma theory
can prove its effectiveness to
reduce the defects ratio and
enhance the performance.
The
six
sigma
principle
can be represented on a
normally distributed product
quality distribution curve
(Fig.1). When the mean is
located at the center of the
normal distribution curve,
the lower and upper limits of to maximize the business level reduces the number
specification are six times the benefits and achieve high of defects to 320 items per
standard deviation (sigma) quality
deliverables.
This million opportunities.

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