Data obtained from actual fielded units or laboratory tested units can be very useful in adjusting predicted failure rates to more accurately reflect what has been experienced. Some calculation models specifically support this capability, including Telcordia, Bellcore, 217 Plus, and PRISM. The Prediction module allows you to use the failure rate adjustment methods provided by these models with all but the FIDES, IEC TR 62380, and RDF 2000 models. For more information, see Failure Rate Adjustments. If the Weibull module is also in use, you can use it to calculate MTBF values from testing or field data. For more information, see Weibull Analysis.