Minitab calculates the planning estimate for the parameter that you want to estimate based on what you provide for the planning values, failure time distribution, and relationship between failure times and stress.
Example output
Uncensored data
Arrhenius model
Estimated parameter: Reliability at time = 1000
Calculated planning estimate = 0.964857
Design stress value = 45
Selected test plans: “Optimum” allocations test plans
Interpretation
For the capacitor data:
- You plan to estimate the reliability at 1000 hours.
- For the 1000-hour reliability, the calculated planning estimate is 0.964857 at the design stress value of 45. Minitab calculates this estimate from your planning values for the slope and intercept. That is, for an exponential distribution and Arrhenius model with an intercept of −8 and a slope of 0.5, the 1000-hour reliability is 0.964857.
- The target confidence level is 95%. Because the resulting sample size must be rounded to an integer value, you cannot achieve a confidence level of exactly 95%. Your actual confidence level is slightly higher than the target confidence level.
