Failure and Repair Distributions

You can select from various failure and repair distributions when modeling the failure and repair characteristics of the blocks in your RBD. When you select a distribution, you will automatically be prompted for the associated parameters needed.

The failure and repair distributions supported, and their corresponding data parameters, include:

• Constant Time: Enter Duration in hours for failure or repair.
• Exponential: Select either Failure Rate or MTBF in the Failure Rate Type field to indicate what data you wish to enter. Enter Failure Rate in the units you have selected for Failure Rate Multiplier, or MTBF in hours. For Repair data, enter the Mean Time to Repair (Hours).
• Gumbel+: Enter the Location (Zeta) and Scale (Delta).
• Gumbel-: Enter the Location (Zeta) and Scale (Delta).
• Lognormal: Enter the Mean (Mu) and Standard Deviation (Sigma).
• Normal: Enter the Mean (Mu) and Standard Deviation (Sigma).
• Rayleigh: Enter the Characteristic Life (Eta) and Location (Gamma).
• Time Independent: Enter Unreliability. (Note: not available as a repair distribution.)
• Uniform: Enter Lower Bound and Upper Bound.
• Weibull: Enter the Slope (Beta), the Characteristic Life (Eta), and Location (Gamma).