Method I, also referred to as the black box or parts count method, arrives at predictive failure rates based on information about the components. Method I calculation results are steady state failure rates. If burn-in data is provided, Method I calculations prior to Telcordia Issue 2 compute the first year multiplier (Π FY). For Telcordia Issue 2, Issue 3, and Issue 4, Method 1 calculations compute the early life factor (Π ELF) and then use this value to determine the first year drop out or infant mortality rate. When burn-in data is entered for a part, you can click Pi Factors in its Prediction Data pane to view Π FY or Π ELF. For more information, see Part Pi Factors.

The different scenarios available within Method I calculations include Case 1, Case 2, and Case 3. The following table describes these scenarios.