Six Sigma
Origin of Six
sigma?
Initially,
the term 6 Sigma was pioneered by Bill Smith at Motorola in 1986
and was defined as a metric for measuring defects and improving
quality, and a methodology to reduce defect levels below 3.4
defects per million opportunities”(DPMO), or put another way, a
methodology of controlling a process to the point of ± six sigma
(standard deviations) from a centerline.
The objective is
to master and decrease the root causes of variability in the
processes by using measurement and statistical tools.
Mastering a so
high level of quality is really important in the processes with
a lot of occurrences and where resulting defects have a high
impact for customer satisfaction or safety. In these cases, a
mastery of 2 sigma (95,44%/45600 DPMO) or 3 sigma (99,73%/ 2700
DPMO), a good level of quality for common processes is not
acceptable.
Six Sigma
Methodology.
 Six
Sigma has now grown beyond defect control. There are plenty of
different definitions of 6 sigma available in the literature. To
summarize, we can say it is a system for achieving, sustaining
and maximizing business success. It is driven by close
understanding of customers needs, disciplined use of facts,
data, and statistical analysis to manage, improve and reinvent
business processes.
The benefits of
Six sigma are too numerous to list, but here's a few of them:
Six Sigma has two
key methodologies:
DMAIC
(Define, Measure, Analyze, Improve, Control) and
DMADV
(Define, Measure,
Analyze, Design, Verify). DMAIC is used to improve an existing
business process. DMADV is used to create new product designs or
process designs in such a way that it results in a more
predictable, mature and defect free performance.
DMAIC
Basic
methodology consists of the following five phases:
Define
formally define the process improvement goals that are
consistent with customer demands and enterprise strategy.
Measure
to define baseline measurements on current process for
future comparison. Map and measure the process in question
and collect required process data.
Analyze
to verify relationship and causality of factors. What is the
relationship? Are there other factors that have not been
considered?
Improve
optimize the process based upon the analysis
Control
setup pilot runs to establish process capability, transition
to production and thereafter continuously measure the
process and institute control mechanisms to ensure that
variances are corrected before they result in defects.
DMADV
Basic methodology
consists of the following five phases:
Define
formally define the goals of the design activity that are
consistent with customer demands and enterprise strategy.
Measure
identify CTQs (critical to qualities), product capabilities,
production process capability, risk assessment, etc.
Analyze
develop and design alternatives, create high-level design
and evaluate design capability to select the best design.
Design
develop detail design, optimize design, and plan for design
verification. This phase may require simulations.
Verify
design, setup pilot runs, implement production process and
handover to process owners.
Six Sigma Main
tools
Six Sigma gathers
a panel of statistical and quality control tools used in
different stages of the DMAIC, DMADV methodologies.
The main ones are:
Cause and
effect analysis
Check sheets
Control chart
Histogram
Pareto diagram
Scatter
diagram
Process
flowchart & process mapping
Quality
Function Deployment (QFD)
Hypothesis
Testing
Correlation
and Regression
Analysis of
Variance (ANOVA)
Design of
Experiment (DOE)
Failure Modes
and Effects Analysis (FMEA)
Balance
Scorecards (BSC)
Voice of
Customer (VOC)
Gauge R+R
CPQP staff assist in the training process using real world
examples at your place of work and assist in the Design & Shop floor implementation
back to services
menu
|
