[PPT]Fundamental Concepts of JIT - James Madison …cob.jmu.edu/busingme/COB 300/downloads/Downloads...
Transcript of [PPT]Fundamental Concepts of JIT - James Madison …cob.jmu.edu/busingme/COB 300/downloads/Downloads...
Chapter 11 – Part IChapter 11 – Part ITotal Quality ManagementTotal Quality Management
COB 300COB 300BusingBusing
Problems Hidden by Inventory
Simplifying the Process
• Plant layout• Group technology• U-shaped layout• Reducing setup time• Total preventive
maintenance
Simplified Process
Strategy and JIT
• Quality and reliability• Flexibility
– product– volume
• Dependability• Asset utilization• People utilization• Cost minimization
Internally OrientedInternally OrientedDefinitions of QualityDefinitions of Quality
Quality is the degree to which a specific product conforms to a design or specification
Differences in quality amount to differences in the quantity of some desired ingredient or attribute
Externally OrientedDefinitions of Quality
• Quality is fitness for use• Quality consists of the capacity to satisfy wants
A Definition of Quality Used by Many Companies
Quality is consistently meeting or exceeding the customer’s needs and expectations.
Dimensions of Service Quality
• Reliability• Responsiveness• Assurance• Empathy• Tangibles
Dimensions of Quality for Goods
• Performance• Features• Reliability• Conformance
• Durability• Serviceability• Aesthetics• Perceived Quality
Costs of Quality
• Prevention– Planning– Procedures– Training
• Appraisal– Testing– Inspection– Audits
• Failure– Internal
• Scrap and rework• Retests• Down time
– External• Returns• Warranty work• Goodwill lost• Lost sales
The Background of TQM
• W. Edwards Deming– System causes most
defects• Joseph M. Juran
– Quality planning, quality control, quality improvement
• Philip Crosby– Quality is free, zero
defects• Genichi Taguchi
– Taguchi methods, robust design
Components of TQM
• Focus on the customer• Everyone responsible for
quality• Team problem solving• Employee training• Fact-based management• Philosophy of continuous
improvement
Components ofContinuous Improvement
• Standardize and document procedures• Assign teams to identify areas for
improvement• Use methods analysis and problem-solving
tools• Use the Plan-Do-Check-Act cycle• Document improved procedures
The Plan-Do-Check-Act Cycle
Baldridge Award
• Baldridge Award Criteria for 00
ISO 9000 Standards9000-1: Guidelines9001: Design through installation and
testing9002: Production through installation
and testing9003: Distributors9004-1: Model of quality management
system
Comparing Baldrige,ISO 9000 and TQM
• Baldrige– U.S. Quality Award– Focus on outcomes
• ISO 9000– International standards– Focus on documentation of processes
• TQM– Organizational quality philosophy– Foundation of Baldrige criteria
Chapter 11 – Part IIChapter 11 – Part IIQuality Control Quality Control
COB 300 C - The Operations DimensionCOB 300 C - The Operations DimensionBusingBusing
Causes of Variation
• Random Causes– difficult or expensive
to control– e.g., outside humidity,
line voltage• Assignable Causes
– easier to correct– e.g., employee error,
new materials
Comparing Process Variation to Tolerance Limits
High Process Capability After Technological Process Change
Control Charts• Variables - concentrates on mean for some
measurable characteristic.– diameter– length
• Attribute - data is based on counts or the number of times we observe a particular event.– proportion defective/non-defective– go/no go– proportion pass/fail
Control Limits - Variables Charts
X-Bar Chart
R Chart
UCLx x 3
LCLx x 3
X A R2
UCL D RR 4LCL D RR 3
X A R2
Variables Control Chart Examples: Compute the 3 control charts for X and R from 15 samples ofsize n=3. Plot the control limits and the Xand R values and comment about the underlying process.
Sample OBSERVED DIMENSIONS (cm)1 4.843 4.863 4.8592 4.925 4.882 4.8913 4.866 4.914 4.8734 4.852 4.883 4.885 4.92 4.884 4.8216 4.915 4.902 4.8987 4.887 4.892 4.8588 4.868 4.888 4.8429 4.904 4.863 4.86610 4.921 4.92 4.89411 4.914 4.884 4.89912 4.892 4.896 4.88713 4.866 4.829 4.8814 4.85 4.875 4.87215 4.867 4.9 4.885
Variables Control Chart Examples: Compute the 3 control charts for X and R from 15 samples of size n=3. Plot the control limits and theXand R values and comment about the underlying process.
Sample OBSERVED DIMENSIONS (cm) mean range1 4.843 4.863 4.859 4.855 0.0202 4.925 4.882 4.891 4.899 0.0433 4.866 4.914 4.873 4.884 0.0484 4.852 4.883 4.88 4.872 0.0315 4.92 4.884 4.821 4.875 0.0996 4.915 4.902 4.898 4.905 0.0177 4.887 4.892 4.858 4.879 0.0348 4.868 4.888 4.842 4.866 0.0469 4.904 4.863 4.866 4.878 0.041
10 4.921 4.92 4.894 4.912 0.02711 4.914 4.884 4.899 4.899 0.03012 4.892 4.896 4.887 4.892 0.00913 4.866 4.829 4.88 4.858 0.05114 4.85 4.875 4.872 4.866 0.02515 4.867 4.9 4.885 4.884 0.033
4.882 0.037
Factors for Control Limits(Slide 1 of 2)
23456789
10
1.8801.0230.7290.5770.4830.4190.3730.3370.308
000000.0760.1360.1840.223
3.2682.5742.2822.1142.0041.9241.8641.8161.777
n A2 D3 D4
Sample of Size
844.4)037(.023.1882.4
920.4)037(.023.1882.4
x
x
LCL
UCL
x-bar Chart Example (cont’d)
Six Sigma Control Chart (x-bar)
4.840
4.850
4.860
4.870
4.880
4.890
4.900
4.910
4.920
4.930
0 2 4 6 8 10 12 14 16
Observation
cm
Sample Mean
Upper Control Limit
Lower Control Limit
Center Line
Range Chart
0951.037.57.24 RD
0037.03 RD
Range Example
0
0.02
0.04
0.06
0.08
0.1
0.12
0 2 4 6 8 10 12 14 16
Sample Number
rang
e (c
m) Upper Control Limit
Center LineLower Control LimitSample Range
Warning Conditions
• Two successive points near limit
• Run of five above or below mean
• Trend• Erratic behavior
Process Control for AttributesProportion defective:
Number of defects per unit:
pp pn
( )1
UCL p
LCL pp p
p p
3
3
UCL cc c 3LCL cc c 3
c c
P-Chart
0
0.02
0.04
0.06
0.08
0.1
0.12
0.14
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
observation
prop
ortio
n de
fect
ive
observation proportion defective
lower control limit
center line
upper control limit
Homework
• Chapter 11 – 4, 8, 9