Stream Turbulence Index

Stream Turbulence Index (STI) reflects the difference between the projected end date of a sprint and the team’s sprint length.

STI is designed to be scalable and can be compared across teams or Agile Streams. STI is used as an early warning indicator of internal drag observed by agile teams.

STI is calculated using the following equation:

STI = (PED/SL) - 1

Where, PED is the Projected End Day of the Sprint, based on the number of unfinished work-items left in the Sprint Backlog. PED is calculated using linear-regression to extrapolate the team’s last day from the burn-down chart. SL is the Sprint Length.