Reliability Modeling and Prediction

A reliability model mathematically defines the interdependencies between hardware/ software/human elements and their combined contributions to failure. A prediction calculates failure rates using that model so that a reliability metric can be quantified to assess design tradeoffs, and as an estimate of operational reliability after a product is delivered.

Reliability Modeling and Prediction

May 21st, 2015

Data & Tools
Publications
Training

What is it?
A reliability model mathematically defines the interdependencies between hardware/ software/human elements and their combined contributions to failure. A prediction calculates failure rates using that model so that a reliability metric can be quantified to assess design tradeoffs, and as an estimate of operational reliability after a product is delivered.
What’s the payoff?
The modeling/prediction/assessment…  Read More

Lunchtime Learning Series

September 16th, 2014
The “Lunchtime Learning” series is a group of short course tutorials are aimed at providing a basic introduction to a variety of topics in which our community members have expressed an interest.   Read More

Interference Stress/Strength Analysis

August 26th, 2014

In simplest terms, an item fails when a stress to which it is subjected exceeds the corresponding strength. In this sense, strength can be viewed as “resistance to failure”. Good design practice is such that the strength is always greater than the expected stress. The safety factor “η” can be defined in terms of strength…  Read More

Solving the Complex RBD-Series Parallel System with a Keystone Component

February 26th, 2009

The general form of this type of reliability block diagram has two series circuits in a parallel arrangement combined through a center or “keystone” unit. You are often given the reliability of each block and asked to calculate the reliability of the circuit.

For example let’s say we are given the following five block arrangement pictured…  Read More

Mission Reliability and Logistics Reliability: A Design Paradox

April 26th, 2005
The goal of improving system reliability often presents a design paradox; “mission” reliability cannot be increased without simultaneously decreasing “logistics” reliability. When faced with the challenge of a system that has inadequate reliability to meet specification requirements, hardware redundancy is often implemented, leading to   Read More

Better Reliability Predictions Using Experience Data

February 26th, 2005

There are many approaches that can be used to predict the reliability of an item. Sometimes when asked to provide a “quick estimate” of an item’s reliability, the use of field experience is overlooked, or if no failures have occurred, overly conservative estimates are made by assuming one failure. This article describes a simple approach…  Read More

Understanding Your Product Through Reliability Modeling

March 26th, 2004
A reliability model represents a clear picture of your product’s functional interdependencies providing a means to trade-off design alternatives and to identify areas for design improvement. The models are also helpful in:   Read More

System Spares – What’s the “Right” Answer?

December 26th, 2002
Manufacturers are often faced with questions such as: How often will my system fail? How many spare parts should I stock? How confident am I that I will have enough spare parts?   Read More

Making Sense Out of the Reliability Prediction Business

August 1st, 2001
Reliability Predictions are commonly used in the development of products and systems to compare alternative design approaches and to assess progress toward reliability design goals. They’re often criticized as not being accurate forecasts of field reliability performance because they don’t usually account for all the factors   Read More