We publish electronic versions of “Reliability Ques” periodically as a means of keeping our community up-to-date on effective tools, techniques, and approaches to improving the reliability, maintainability, and quality of products and systems.
Design of Experiments for Reliability Improvement
Test Samples: How Many Are Needed?
For demonstrating product reliability the question of how many test samples are needed to be “X” percent confident of having met a reliability objective often comes up. Let’s say that manufacturer is going to produce 5,000 rooftop car carriers and is willing to tolerate roughly 100 returns over the next five years. How can this… Read More
Need Technical Help? Try an IAC
Last month we introduced you to the Department of Defense (DoD) Reliability Information Analysis Center (RIAC), formerly known as the Reliability Analysis Center (RAC), as a valuable resource for expertise and data/information in reliability, maintainability, quality, supportability, and interoperability.Now we want to tell you more about the technologies covered by all twenty-one Centers of Excellence… Read More
Reliability Certification
Starting salaries for engineers graduating from college this spring will be in the $50K neighborhood and even higher for the top students, as well as those with specialized experience. The degrees are typically electrical, electronics, mechanical, materials, civil, industrial, computer, and so on. Seldom is there a “reliability engineering” graduate. There are a few exceptions… Read More
Mission Reliability and Logistics Reliability: A Design Paradox
Probability and Statistics for Reliability: An Introduction
Better Reliability Predictions Using Experience Data
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
Reliability: Costly, or Cost Effective?
There are those who would argue that the costs of reliability activities associated with developing new products have little payoff. Whether we’re talking about commercial products or military systems, we don’t agree. Concepts like Life Cycle Costs, Total Ownership Costs, Reliability-based Maintenance, Performance-Based Logistics, and others clearly recognize the contribution of reliability activities in reducing… Read More