Control Chart
Statistical P S i i l Process Control C l
26 August 2009 University Malaysia Perlis P li
Presented by Dr Zaharah Wahid
DRZ CONSULTANT
1
An Overview of Statistical Process Control (SPC)
DRZ CONSULTANT 2
What is SPC
Statistical : A universal language to describe and analyse the physical variability of a process. Process : The transformation of inputs including f f man, machinery, methods, materials, energy and information to attain a desired result result. Control : To make a process behave the way we want it to behave.
DRZ CONSULTANT
3
Key Concept K C t
• construct control charts so that we can monitor important features of data over time
whether some process is statistically stable (or within statistical control).
4
• use such charts to determine h h t t d t i
DRZ CONSULTANT
Key Concept K C t
A common goal of many different methods of quality control is to Reduce variation in a product or a service. service
DRZ CONSULTANT
5
SPC - A Funnel for Quality Q y
Material Input with Variation
MEASURE
ANALYSE
SPC
IMPROVE
CONTROL
Quality Output less variation
DRZ CONSULTANT 6
Process Control System
SPC
DRZ CONSULTANT
7
Collection of Data
The data must satisfy the above condition: y
The data must be the right data Measuring instruments are in good conditions The d t Th data must b analysed in such t be l di h manner that results can be easily understood d t d These results must be interpreted in the context of the original data
DRZ CONSULTANT 8
Types of D t T f Data
Qualitative-non numerical, measured according to specific categories categories. e.g colour, sex, gender, marital status, opinion etc Quantitative - numerical, either continuous ( measured) or discrete (count)
DRZ CONSULTANT
9
TYPES OF MEASUREMENT SCALE
Random variable
Categorical
Type of variable
Numerical
nominal scale
ordinal scale
Interval scale discrete
Ratio scale continouos
10
26 August 2009 University Malaysia Perlis P li
Presented by Dr Zaharah Wahid
DRZ CONSULTANT
1
An Overview of Statistical Process Control (SPC)
DRZ CONSULTANT 2
What is SPC
Statistical : A universal language to describe and analyse the physical variability of a process. Process : The transformation of inputs including f f man, machinery, methods, materials, energy and information to attain a desired result result. Control : To make a process behave the way we want it to behave.
DRZ CONSULTANT
3
Key Concept K C t
• construct control charts so that we can monitor important features of data over time
whether some process is statistically stable (or within statistical control).
4
• use such charts to determine h h t t d t i
DRZ CONSULTANT
Key Concept K C t
A common goal of many different methods of quality control is to Reduce variation in a product or a service. service
DRZ CONSULTANT
5
SPC - A Funnel for Quality Q y
Material Input with Variation
MEASURE
ANALYSE
SPC
IMPROVE
CONTROL
Quality Output less variation
DRZ CONSULTANT 6
Process Control System
SPC
DRZ CONSULTANT
7
Collection of Data
The data must satisfy the above condition: y
The data must be the right data Measuring instruments are in good conditions The d t Th data must b analysed in such t be l di h manner that results can be easily understood d t d These results must be interpreted in the context of the original data
DRZ CONSULTANT 8
Types of D t T f Data
Qualitative-non numerical, measured according to specific categories categories. e.g colour, sex, gender, marital status, opinion etc Quantitative - numerical, either continuous ( measured) or discrete (count)
DRZ CONSULTANT
9
TYPES OF MEASUREMENT SCALE
Random variable
Categorical
Type of variable
Numerical
nominal scale
ordinal scale
Interval scale discrete
Ratio scale continouos
10