Module 8 Lesson 1 Flashcards
Been defined as the monitoring of quality by the application of statistical methods in all stages of production
Statistical quality control
What is the objective of SQC?
To determine whether the major source of observed variation is due to “chance variation” or to “assignable cause”
Most common pattern of data distribution is
Normal curved - a symmetric, bell-shaped curve
The normal distribution is defined completely by two parameters:
Mean and the standard deviation
The arithmetic average of a series of values
mean
It is an average single determination found by extracting the square
root of the quotient, obtained by dividing the sum of the squares of
the individual deviations from the mean by one less than the number
of the determination made.
Standard deviation
The middle result when replicate data are arranged in order of the size
Median
Is the difference between the largest an smallest value in a data set or group of data
range
Refers to the reproducibility of a series of measurements
precision
Refers to the closeness of measurements to the true or accepted value
accuracy
Refers to systematic difference from the true value
bias
Can be used as a tool to determine, achieve and maintain acceptable levels of quality laboratory and performance
Shewhart control chart
Formula for mean
Add all number and dividing the sum by the total number of data
Formula for SD
S= √(x-mean)2 / n-1
Are based in a continuous distribution of measuements that can measure degree of unacceptabiltiy
Variable charts
Refer to go or no go situations in which each sample is inspected is tested to determine whether it conforms to the requiremtns
Attribute charts
