7 Basic quality tools

Check sheet

A structured, prepared form for collecting and analyzing data; a generic tool that can be adapted for a wide variety of purposes.

Stratification

A technique that separates data gathered from a variety of sources so that patterns can be seen (some lists replace "stratification" with "flowchart" or "run chart").

Scatter diagram:

Graphs pairs of numerical data, one variable on each axis, to look for a relationship.

Control charts

Graphs used to study how a process changes over time

Cause-and-effect diagram also called Ishikawa or fishbone chart

Identifies many possible causes for an effect or problem and sorts ideas into useful categories.

Pareto chart

Shows on a bar graph which factors are more significant.

Histogram:

The most commonly used graph for showing frequency distributions, or how often each different value in a set of data occurs.