Reliability Prediction, MIL-HDBK-217, Reliability Assessment, Similar Item Analysis Consulting


RAM Predictions

Reliability and maintainability predictions are forecasting methods that involve analysis of system characteristics and the use environment to estimate the reliability and maintainability of a system, prior to the item being developed, built or fielded. The availability prediction would then be modeled from these inputs combined with the relevant support information. Reliability predictions can be developed from a number of sources. Some of these sources include:

  • Past test or field data from a similar product.
  • Engineering analysis, failure modeling, and/or accelerated life test.
  • Subject matter expertise based on known reliability levels for comparable equipment and technologies.
  • Handbooks

Each of these approaches has limitations. Most importantly one should recognize that high reliability is not achieved through predictions. A reliability prediction may have little or nothing to do with the actual reliability of the product.

RAM Prediction Features

  • Can be either a deterministic or probabilistic analysis.
  • Provides estimates at confidence if desired.

RAM Prediction Uses

  • Estimating the relative merits of competing designs.
  • Selecting different components or limiting applied stresses.
  • Helping to understand life-limiting failure mechanisms.
  • Assessing new component technologies when no historical data exists.
  • Identifying whether a commercial-off-the-shelf component may achieve the required reliability when stresses exceed the commercial rating(s).
  • Estimating types and quantities of spares.