Deficiencies in traditional reliability prediction approaches Traditional methods of reliability prediction model development have typically yielded component failure rate model forms that are multiplicative in nature; that is, the predicted failure rate is the product of a base failure rate and several adjustment factors that account for the stresses and component variables that influence reliability.
New reliability prediction methodology incorporates field and test experience
Funded by the Department of Defense (DoD) and sponsored by the Defense Technical Information Center (DTIC), the Reliability Information Analysis Center (RIAC) released 217PlusTM in July 2006 as the DoD-designated replacement for the earlier Reliability Analysis Center (RAC) PRISM®* methodology. In conjunction with this release, the new component and system failure rate models were published for the first time in the RIAC Handbook of 217 Plus Reliability Prediction Models, providing the detail missing from the RAC predecessor to support users in understanding the validity of the methodology in comparison to outdated, pessimistic reliability prediction methods such as MIL-DBK-217, Reliability Prediction of Electronic Equipment.1 This article highlights features of the new methodology that correct several recognized deficiencies of MIL-HDBK-217. A simple example illustrates how the improved prediction results compare to more traditional reliability prediction approaches, and discussion is provided that shows favorable correlation between the new methodology and actual field experience.