CHƯƠNG 7 SIX SIGMA Còn 3 sile cuối
1/Six Sigma Overview
Key themes in Six Sigma
Identifying the root causes of problems
Emphasis on process improvement to remove variation and therefore lower defects and improve customer satisfaction
Using measurements and statistics to identify and measure variation
Pro-active management focusing on problem prevention
Focus on the customer’s requirements
Cross-functional collaboration
Setting very high targets.
Process Improvement
Only when the cause of the variation has been identified,
can the process be improved so that the variation doesn’t
recur in the future.
Six Sigma aims for processes to be improved so that problems don’t recur instead of just finding short term solutions to the problems
Measurements and Statistics
To improve results, a company needs to
identify ways to measure variation in
business processes, generate statistics
based on those measurements and then
use those statistics to ask questions about
the sources of quality problems relating to
its products, services, and processes.
Benefits
Reduced production costs
eliminate wastage
reduce the cost
lowering defect rates
sell its products
Reduced overhead costs
reduce the amount of time that senior
management and middle management
frees up management
Improved Customer Satisfaction
lowering defect rates
ship products to customers
Reduced Cycle Times
On-Time-Delivery
Greater ease of expansion
Positive Changes to Corporate Culture
the company’s corporate culture shifts to one
contribute to the overall sense of pride of the company’s employees.
1 DMAIC-DEFINE ✅
Focus on critical issues which are aligned
with the company’s business strategy and
the customer’s requirements.
Most applicable tools
Identify the problem, the requirements of the project and the objectives of the
project.
Trend Chart
Pareto Chart
Project Charter
Process Flow Chart
Define customer requirements as they relate to this project. Explicit customer requirements are called Critical-to-Quality (CTQ) characteristics
Develop defect definitions
Perform a baseline study
Create a team charter and Champion
Estimate the financial impact of the problem
Obtain senior management approval of the project
2 DMAIC – Measurement : ✅
Tools used
Identify Critical-to-Quality (CTQ) characteristics
Identifying and measuring the source of variation
Understand the current performance
Fishbone Diagram
Process Mapping
Cause & Effect Matrix
Preliminary Failure Mode & Effect Analysis (FMEA)
Gauge Repeatability & Reproducibility (GR&R)
Map relevant processes with identified Inputs and Outputs
Generate list of potential measurements
Analyze measurement system
Identify where errors in measurements can occur;
Start measuring the inputs, processes and outputs and
collecting the data;
Start measuring the inputs, processes and outputs and
collecting the data;
Refine the problem or objective
3 DMAIC – Analyze ✅
Tools used in this phase
Validate these hypotheses
Identify the vital few root causes and critical inputs
Generate hypotheses
Five Why’s
Tests for normality
Correlation/Regression Analysis
Analysis of Variances (ANOVA)
FMEA (Failure Mode and Effect Analysis)
Hypothesis testing methods
4 DMAIC-Improve ✅
Identify ways to remove causes of variation
Tools used
Verify critical Inputs
Developing ideas to remove root causes
of variation, testing and standardizing
those solutions.
Discover relationships between variables
Process Mapping
Process Capability Analysis (CPK)
DOE (Design of Experiment)
Establish operating tolerances
Optimize critical Inputs or reconfigure the
relevant process.
5 DMAIC- CONTROL ✅
Tools used
Establish standard measures to maintain
performance and to correct problems as
needed
Operating Flow Chart(s) with Control Points
Statistical Process Control (SPC) charts
Check Sheets
Control Plans
Six Sigma Implementation ✅
establish financial targets; set time
lines; train senior executive team and Deployment
Champions
Organize
senior management approves the Six Sigma initiative Decide
create detailed deployment plans Initialize
recognize the need for Six Sigma and
explore its potential impact on the company.
Discover
elect and execute improvement projects Deploy
rain Six Sigma Green Belts and ProcessImprovement Team Leaders Sustain
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Six Sigma is a statistically-based process
improvement methodology that aims to
reduce defects to a rate of 3.4 defects per
million defect opportunities by identifying
and eliminating causes of variation in
business processes.
It is a methodology for improving product quality
by reducing defects based on process
improvement.
Method to Improve Process Quality ✅