Supplemental Quality Tools

Defect density map
Inspection/test forms to tally quantities of various types of defects & to specify their locations relative to unit geometry
Events log
A detailed time-based listing of process related events which differ from the norm
Data stratification
Converts a heterogeneous population into a collection of homogeneous samples/sub-populations
Randomization
Insures that every unit in a sample drawn from a population has an equal opportunity/likelihood of selection
Process flowcharts and maps
Graphically depicts a process, linear or non-linear, indicating the sequence of steps as well as the input and output for each step
Process improvement center
Incorporates the use of a display board located in the proximity to a specific process
Statistical sampling
Use a statistically based procedure to decide what sample size is needed from a population & then select that number of units (the sample) from the population for such purposes as inspection and test.

Excerpted from the ASQ webinar Essential Quality Tools: Supplemental Tools Overview.