Reliability MTBF and Derating Analysis

Product Reliability defined: The ability of a system or component to perform its required function under stated conditions for a specified period of time.

Percept’s definition of Reliability: Something you need to know sooner rather than later.

Percept’s Reliability Process

Percept’s reliability services include much more than simple reliability testing. The key features in the process are the systematic identification of design decisions that can have an expensive impact on product quality downstream. Identification of component selection issues early in the product development process allows for early mitigation that results in enormous savings to time and cost. MTBF (Mean Time Between Failure) and Derating Analysis are two very important tools in the product reliability toolbox.

MTBF (Mean Time Between Failure)

Percept’s MTBF reliability prediction analysis product has many applications including substantiating a design requirement, identifying reliability drivers, making competitive product evaluations, selecting warranty periods, advertising and marketing. After you provide us with the product’s Bill of Material (BOM), Percept applies advanced reliability software modeling, real world data and our expertise to calculate the MTBF prediction of your product. You obtain a comprehensive written report along with a consultation with our reliability experts.

Percept's expertise with predictive models allows us to evaluate the failure rate and MTBF of your product and target areas for potential reliability improvement. We keep up to date with the most widely accepted reliability models in the industry, including:

• MIL-HDBK-217
• Telcordia®/Bellcore
• SR-332

Derating Analysis

Derating is a technique employed in electrical and electronic devices, where the devices are operated at less than their rated maximum specifications. This is done to reduce the rate at which they deteriorate over time and improves the device’s reliability and life expectancy. Derating is a practical means of reducing failures that is supported by much literature including multiple standards as well as by the component’s manufacturers.

Conceptually, if a component or system is operated under its design limit, it will be more reliable than if it is operated at or above the design limit. While a component may be specified to operate at high voltage and high temperature, applying these conditions simultaneously probably would be worse than applying only one or the other independently. Derating increases the margin of safety between the part design limits and applied stresses. This thereby provides extra protection for the part.

A Derating Analysis validates measures to the extent to which components have been specified with sufficient margin to ensure that the product will withstand its expected operating environment. The product is operated under normal conditions and measurements are taken of the operating temperatures which are compared to the ratings of the individual components. The result helps discover operational limits and margins which are then the predictor of the weak links within the product’s design.