Presuming a Par Value of an Application of 100% (i.e. it is what it is) then the impact to the value of a Blocking defect is: The Value of the Application (V) divided by the number of users of that application (N). V/N = the value of a blocking bug. This is based on the idea that a Blocking bug effectively drops the individual’s perceived value of the application at that time to zero. They cannot use the App so they will not want to pay for it in that state. An application can recover by fixing the issue but until the fix is performed the company is at risk of losing the customer’s money and therefore realizing a loss from the risk of the Blocker.