Accurate and timely reliability predictions are an important part of a well structured reliability program. If properly performed, they can provide insight into the design and maintenance of reliable systems. While there are well-accepted reliability prediction methodologies for standard electronic components such as
MIL-HDBK-217, "Reliability Prediction of Electronic Equipment," there are few such sources of failure rate data for other component types.
A potential use for the NPRD 2011 document is to complement existing reliability prediction methodologies by providing failure rate data in a consistent format on various electrical, electromechanical, and mechanical parts and assemblies. All part types and assemblies for which RIAC (Reliability Information Analysis Center) has data are included in this publication with the exception of selected electronic components. Although the data contained in this publication were collected from a wide variety of sources, RIAC has done everything possible to screen the data such that only high quality data is added to the database and presented in this document. In addition, only field failure rate data has been included.
This document is meant to provide historical reliability data on a wide variety of part types to aid engineers in estimating reliability of systems. Sound reliability engineering practices must include knowledge of the failure physics of all components, modules and interconnection assemblies in a system background of life limiting failure mechanisms and how these mechanisms will behave in the intended use environment is also necessary. Only in this manner can robust designs be insured.
It is not feasible for documents like MIL-HDBK-217 or other prediction methodologies to contain failure rate models on every conceivable type of component and assembly. Traditionally, reliability prediction models have been primarily applicable only for generic electronic components. Therefore, NPRD-2011 serves a variety of needs:
1) To provide failure rates on assemblies (ex. disk drives) in cases where piece part level analyses are not feasible or required
2) To complement MIL-HDBK-217 or other prediction methodologies by providing data on part types not addressed by its models.
The failure rate data contained in this document represent a cumulative compilation of data collected from the early 1970's through December 2008. However, it should be noted that some data may be periodically purged from the database in the event that newer data of higher quality is obtained, or if data is on obsolete part types. RIAC is continuously soliciting new field data in an effort to keep the databases current. The goals of these data collection efforts are as follows:
1) To obtain data on relatively new part types and assemblies
2) To collect as much data on as many different data sources, application environments, and quality levels as possible
3) To identify as many characteristic details as possible, including both part and application parameters.
