Quality Tools 1 Flashcards
Name the three rationales of process control:
look at the process not the product
identify potential causes of error
fix the causes
Name two types of acceptance sampling for final product control:
1 Outgoing inspection (immediatly following production)
2 Incoming inspection (inspect aftern receiving)
What is the negative aspect of acceptance sampling?
Reinforces conformance to specifications
No Feedback to the process
Definition SPC
Statiscial process controll is a philosophy, a strategy and a set of methods for ongoing improvement of systems, processes and outcomes.
What does the SPC approach base on?
learning through data
has a foundation in the theory of variation.
Name graphical methods of SPC
Control Charts Run Charts Frequency Plots Histograms Pareto Analysis Scatter Diagrams Flow Diagrams
What can be subsumed from these two definitions:
Q. Improv. is the reduction of variability in processes and products
Q. Improv. is the elimination of waste.
Thus, Quality is inversely proportional to variability.
What are the parameters of quality characteristics (CTQ -critical-to quality)?
1 physical (lenght, weight, voltage, viscosity) 2 sensory (taste, appearence, color) 3 Time orientation (reliability, durability, servicability)
Define Attributes Data:
Discrete Data, often in the form of counts
Define Variables Data
Continuous measurements such as length, weight.
What are the three general specifications:
Nominal or target value
Upper Specification Limit (USL)
Lower Specification Limit (LSL)
Whats the definition of defects?
A defect occurs during any process when the outcome of the process is not the expected outcome.
Calculation Process yield:
Process yield = Good parts out/total parts in
Whats the objective of descriptive statistics:
Describe, organize and summarize in a comprehensive manner the information presented in a sample using tables graphics etc
Whats the objective of statistical interference?
Characterize the whole population from where the sample was drawn. (Relationship between population and sample.
