Quick Parameter Estimator Expert View

Follow the steps below to use the Expert view of the Quick Parameter Estimator (QPE):

• Choose a distribution from the Distribution drop-down list. This is the distribution that you will solve the parameter(s) for. Then choose the appropriate time units from the Units drop-down list.
  • If you are not sure which distribution to select, consider using the Wizard view of the QPE instead.
  • Your choice of time units applies to all time inputs and applicable parameters of the distribution (such as the eta parameter when the Weibull distribution is used).
• Select an appropriate option in the Quantification Method area.
  • The Unreliability and a Parameter method solves for one parameter of the distribution. It requires one unreliability point (i.e., an unreliability value at a specified time) and the values of all the parameters of the selected distribution except the parameter you will solve for.
    • If you select this method, you must then enter one unreliability point in the Point #1 area. For example, if you believe that your product has an unreliability of 10% at 100 hours, then you would enter 100 in the Time field and 0.10 in the Unreliability field.
    • In the Solve for Parameter area, select the parameter that you wish to solve for. The remaining parameters in this area will have input fields enabled. Enter the known values of these parameters.
  • The Two Unreliability Points method solves for all the parameters of the distribution. It requires two unreliability points that you will provide in the Point #1 and Point #2 areas.

Tip: If you are building an event occurrence or task duration model, you can treat an "unreliability" point as the probability that an event will occur or that a task will be completed by a specified time. For example, if you are modeling the probability of an event's occurrence and you believe that there is a probability of 30% that the event will occur before 150 hours, then you would enter 0.3 in the Unreliability field and 150 in the Time field.

• Click Calculate to solve for the unknown parameter(s).
• Click the Update button to update the model using the selected distribution, calculated parameters and selected time units.