Class 2: Quality Management Flashcards
What are the 8 dimensions of quality?
- Performance
- Features
- reliability
- Conformance (how well it meets a standard
- Durability
- Serviceability
- Aesthetics
- Value
What is quality?
The total features and characteristics of a product or service that bears on its ability to satisfy stated or implied needs. It is customer determined, always representing a moving target.
How to achieve conformance?
Design products that consumers value and control variability in the process.
Process variability
What are the causes of variation
pure natural randomness or assignable causes of variation (could be assigned to a particular source
What does it mean to be in statistical control
A transformation process is affected by common causes or variation ONLY and is continuously producing outputs that are random with no patterns.
What are statistical control charts
graphical tools to statistically distinguish between assignable and common causes of variation. Lets the user judge whether the observed variation could be due to e.g breakdown of a machine or an operator mistake
What is process capability
The ability of a transformation process to produce outputs whose critical characteristics of interest fall within pre-specified upper & lower design specification limits, assuming the design specification limits are consistent with what customers require.
What does process capability measure?
It is a measure of the relationship between natural variation of the process and the design specifications.
relationship between natural variation and standards
the natural variation of a process should be small enough to produce products that meet the standards required
process capability analysis
Allows us to quantify the capability of our process to produce product that meet our design standards
What is Cp
a measure of the potential of the process. what the process might be able to achieve if the process was centred
What is the process capability ratio
Cp = Upper specification - Lower specification / 6Sigma
What does Cp mean?
A capable process must have a Cp of at least 1.0
what does six sigma correspond to
Six sigma: methodology focused on improving process quality = 2.0. No more than 3.4 defects per million. This is done by reducing standard deviation and variability.
