Ch. 13-Process Capability And Statistical Process Control

Front 1

assignable variation

Back 1

caused by factors that can be clearly identified and possibly managed

(i.e. a poorly trained employee that creates variation in finished product output)

Front 2

common variation

Back 2

variation that is inherent in the production process

(1.e. a molding process that always leaves "burrs" or flaws on a molded item)

Front 3

Taguchi's View of Variation

Back 3

traditional view is that quality within the range is good and that the cost of quality outside this range is constant

views costs as increasing as variability increases, so seek to achieve zero defects and that will truly minimize quality costs

Front 4

Capability Index

Back 4

shows how well parts being produced fit into limit specifications

Front 5

attribute measurement

Back 5

measurement by attributes means taking samples and using a single decision - the item is good/bad

P-chart application

Front 6

variable measurement

Back 6

usually measures the actually weight, volume, number of inches or other "variable" measurements.

--generally want small sample size (4-5)
--quicker and cheaper
--want 25 or so samples to set up chart

X-bar and R-chart applications

Front 7

Capability Index Formula

Back 7

Front 8

process control using P-charts

Back 8

Attribute measurement, each item is either good/bad

Front 9

process control using C-charts

Back 9

attribute measurement, product can have multiple defects