Glossary Terms Archive

Error

Statistics error The dual dimension of error statistics is philosophy and methodology. It is a perspective that includes both a group of statistical tools and their interpretation and justification. A general philosophy of science and the role of probability in...

Effect

It’s the change in the average value of the output caused by a change in an input. Effect Size A statistical concept that measures how strong a relationship exists between two variables using a numeric scale. The effect size is the difference in height between...

What Is Process Drift? Detecting Drift on a Control Chart

Process drift is a slow, steady change in a process’s average or output over time, without anyone planning it. It matters because drift often goes unnoticed at first, each small step looks harmless, but by the time the process has drifted far enough to cause...

DPMO (Defects Per Million Opportunities): Formula, Sigma Level Table

DPMO (Defects Per Million Opportunities) is a standardized Six Sigma metric that measures how many defects a process would produce per one million opportunities for error. It matters because it lets teams compare defect rates fairly across processes of very different...

Design of Experiments (DOE) for Six Sigma

Design of Experiments (DOE) serves as a cornerstone methodology within Six Sigma projects, enabling organizations to optimize processes systematically while reducing variation and improving quality. This powerful statistical technique transforms how businesses...