1. QUALITY MANAGEMENT (bpb 44002)
Dr. Rosmaini Tasmin Faculty of Technology Management and Business UTHM Johor

2. Learning Objectives Interpret visual data displays
Interpret sample mean, variance, standard deviation and range
Concepts of random variable and probability distribution
Determine probabilities

3. Outline Describing Variation Probability Distributions
Normal Distributions
Statistical Inference
for Single Sample

4. Statistical Process Control
Dr. Shewhart
1930’s
Small Sample Sizes
Bell Laboratories

5. Statistical Process Control
Methodology for charting a process and quickly determines when a process is not in control.
Quality is a way of life
Doing it right, the first time
Is 99.9 % enough?
100 % ~ zero defect
Six Sigma means %
Motorola Six Sigma means 3.4/1 million

6. Sample Standard Deviation
May the use SD (single event),
How about Multiple Events?

7. Sample Mean Measure of central tendency
“Average” value of the data set

8. Probability Distributions
A mathematical model that relates the value of the variable with the probability of occurrence within the population.
Value of market share
Number of rejects

9. Normal Distribution
The most important distribution in theory and applications of statistics.
Normally distributed in a bell curve pattern
Symmetrical around the mean
68%
95%
99.7%

10. Normal distribution
1 time std. dev.
2 time std. dev.
3 time std. dev.

11. What is VARIATIONS
Variations in an observed situation are the fluctuations of recorded data between minimum and maximum with typically a dominant value.
There is no two natural objects, are the same.
All matters vary, even exact twins…!
Two exact model smartphones, also vary.

12. Distribution Curve at 3 Sigma
3 Sigma level ~ %
SPC does not eliminate all variations, but identify and separate that special causes of variation

13. Chance & Assignable Causes of Quality Variation
A process that is operating in the presence of assignable causes is said to be an out-of-control process.

14. Extruder machine

15. Hamana Extruder’ machines
HEMS-01
HEMS-02
HEMS-03
3 exact bunching machines, on production floor, behaves differently.

16. X-Bar Chart (Practice)N

17. P-bar chart N
Data are the fraction defective of some set of process output

18. SPC Benefits Alert and Prompt Investigation and corrective action
Lessen trial and error
Process improvement
On the process improvement
Control chart shows whether expected results can be achieved
Support improvement
Continuous
The process is in statistical control

19. Working Process Control Chart

20. Any question?, if not…