Process capability
Process
The term specication refers to the requirements that a
capability
Cp index
product must satisfy to meet the clients needs.
Example
Criticism
Cpk
Example
Criticism
Given a qu
ANOVA
Designed experiments are typically analyzed using ANOVA
techniques.
ANOVA is an abbreviation referring to
analysis of variance.
The purpose of these slides is to provide a gentle
introduction to
Welcome to MATH 427
Introduction
Chapter 1
Welcome to MATH 427 (Statistical Quality Control).
Denitions
Motivation
The course will meet Tue/Thu, 12:35 13:55.
Variability
Tolerance
Course material (sli
Acceptance sampling
Acceptance
Acceptance sampling (AS) refers to statistical techniques
sampling
Types of AS plans
Advantages
Disadvantages
whose ultimate purpose is the acceptance or rejection of lo
Process capability
Process
The term specication refers to the requirements that a
capability
Cp index
product must satisfy to meet the clients needs.
Example
Criticism
Cpk
Example
Criticism
Given a qu
Solving problems
Issues faced
Companies typically face two types of quality problems:
Examples
Quality circles
sporadic quality problems;
Role of data
Problem
chronic quality problems.
solving
The fab
Introduction to control charts
Introduction
Principle
A control chart is a graphical tool designed to track the
changes in a quality characteristic over time. It is used to
Denitions
Type of
variation
Rational sub-groups revisited
Introduction
To be useful, a control chart must address the right
Allocation of
question.
the variation
Example
Data must be collected and organized in rational sub-group
EWMA charts
EWMA charts
CUSUM
charts
Suppose X1 , . . . , Xn are collected at regular time intervals. If
the process mean drifts slowly over time, the overall mean
V-masks
Design
Example
ARL
Tabular
C
General procedure for X - and R-charts
Introduction
Revising limits
Using the
median range
Example
Robustness
Simulation
study
Other
detection
rules
Assume that the process is stable;
this justies th
Welcome to MATH 427
Introduction
Chapter 1
Welcome to MATH 427 (Statistical Quality Control).
Denitions
Motivation
We will meet here every Wednesday, 11:35 14:25.
Variability
Tolerance
Course material
Factor allocation in a fractional plan
Recall that fractional plans are factorial designs in which
only a fraction of the runs is carried out.
Consequently, only a fraction of the main effects and
int
Double-sampling plans
A double-sampling plan is a procedure in which, under
Doublesampling
certain circumstances, a second sample is required before
plans
the lot can be sentenced.
OC curves
Example
I
General procedure for X - and R -charts
Introduction
Revising limits
Using the
median range
Example
Robustness
Simulation
study
Other
detection
rules
Assume that the process is stable;
this justies t
Rational sub-groups revisited
Introduction
To be useful, a control chart must address the right
Allocation of
question.
the variation
Example
Data must be collected and organized in rational sub-group
Control charts for attributes
Introduction
The np-chart
So far, we focussed on control charts for measurements.
The p-chart
The c -chart
We will now consider control charts for attributes.
The u -char
Solving problems
Issues faced
Companies typically face two types of quality problems:
Examples
Quality circles
sporadic quality problems;
Role of data
Problem
chronic quality problems.
solving
The fab
EWMA charts
Suppose X1 , . . . , Xn are collected at regular time intervals. If
the process mean drifts slowly over time, the overall mean
1
X=
n
n
Xi
i =1
will not give an accurate estimate of the pr
Introduction to experimental design
A designed experiment is a series of tests in which changes
are made on purpose to the input variables of a process.
The objective is to observe and identify corres
Introduction to control charts
Introduction
Principle
Denitions
Type of
variation
A control chart is a graphical tool designed to track the
changes in a quality characteristic over time. It is used to
CUSUM charts
Introduction
Example
The CUSUM chart was introduced by E.S. Page, from the
V-masks
University of Cambridge (Page 1954, Biometrika).
Design
Example
ARL
Tabular
Much like EWMA charts, its p
Blocking techniques
A blocking factor is an external variable that is used to group
units into blocks so that the experimental group and the
control group are matched.
In the previous example, suppose
Two-way ANOVA model
Suppose that we wish to study the effect of two factors A
and B on a response variable Y .
Assume that factor A can take a different values, and that
factor B can take b different
Double-sampling plans
A double-sampling plan is a procedure in which, under
Doublesampling
certain circumstances, a second sample is required before
plans
the lot can be sentenced.
OC curves
Example
I