Standard deviation is the measure of variation in a process. Describing variation by standard deviations lets us easily compare processes.
Box plots are graphical tools that let you easily visually compare variation between the data sets evaluated.
A stem and leaf plot is a technique to categorize either continuous or discrete values. It is used to organize data as they are collected.
A data collection form is a best practice of data collection. It’s a way of recording your approach to obtaining the data you need to perform your analysis.
A run chart is a basic graph displays data as they evolve over time. Simple rules can be useful for identifying trends or shifts in process.