Requirements volatility is calculated as the percentage of change in the total number of requirements during a sprint. The formula to calculate volatility is:

Volatility=(Introduced+Removed+Changed)Initial100text{Volatility} = frac{(text{Introduced} + text{Removed} + text{Changed})}{text{Initial}} times 100Volatility=Initial(Introduced+Removed+Changed)100

Using the given data:

Initial requirements = 354

Introduced = 14

Removed = 6

Changed = 28

Volatility=(14+6+28)35410013.5%text{Volatility} = frac{(14 + 6 + 28)}{354} times 100 approx 13.5%Volatility=354(14+6+28)10013.5%

'Agile Estimating and Planning' by Mike Cohn, which explains the concept of requirements volatility in agile projects.