Standard Deviation Value is used in reports to provide greater depth of analysis.
STDDev (STDDev is acronym of Standard Deviation) shows how much variation there is from the “average” (mean). A low standard deviation indicates that the data points tend to be very close to the mean, whereas high standard deviation indicates that the data are spread out over a large range of values.
In other words higher value shows that something is causing response times to jump around and this indicates unstable service service performance.
Dotcom-Monitor utilized the following formula for calculation
Standard Deviation Value
x – Duration
n – response quantity