What does 'standard deviation' measure in Six Sigma?

Standard deviation is a crucial concept in Six Sigma, as it quantifies the amount of variation or dispersion in a set of data values. In the context of Six Sigma, a low standard deviation indicates that the data points tend to be close to the mean, showing that processes are running consistently and predictably. Conversely, a high standard deviation suggests more variation which can point to issues within a process, highlighting areas that may need improvement to reduce defects and improve quality.

Understanding standard deviation helps teams identify how much variety exists in process performance. Essentially, it informs the team about the level of risk and consistency in outcomes, which is key in striving for process improvement and quality control initiatives. By analyzing the variability represented by standard deviation, Six Sigma practitioners can make informed decisions regarding process changes and initiatives aimed at reducing defects.