Derating Analysis

Derating is the selection and application of parts and materials so that the applied stress is less than rated for a specific application. To use derating analysis in Lambda Predict, you will first apply a derating standard to a selected standard item in the system hierarchy (you can select any except the NSWC standard item , the Siemens standard item or the MIL-217 Parts Count standard item ). The selected derating standard will be applied automatically to all the components under that item. You can define your own custom derating standard or select from any of the following published derating standards:

• Naval Air System Command AS-4613: General Specification for Application and Derating Requirements for Electronic Components, issued by the U.S. Naval Air Systems Command in 1976. This standard provides derating curves for three classes of electronic and electromechanical parts: AS-4613 Class A, AS-4613 Class B and AS-4613 Class C.
• MIL-STD-975M: NASA Standard Electrical, Electronic, and Electromechanical (EEE) Parts List, issued by the U.S. National Aeronautics and Space Administration in 1994. This standard provides part selection information and derating curves for electrical, electronic and electromechanical parts used in the design and construction of space flight hardware in space missions, as well as essential ground support equipment (GSE).
• MIL-STD-1547A: Electronic Parts, Materials, and Processes for Space and Launch Vehicles, issued by the U.S. Department of Defense in November 1998. This standard provides part selection information and derating curves for electronics parts, materials and processes used in the design, development and fabrication of space and launch vehicles.
• NAVSEA-TE000-AB-GTP-010: Parts Derating Requirements and Application Manual for Navy Electronic Equipment (Rev. 1 with Change A), issued by the Naval Sea Systems Command in March 1991. This standard provides derating curves for the ten most commonly used electrical and electronic parts.
• ECSS-Q-30-11-A: Space Product Assurance, issued by the European Cooperation for Space Standardization in April, 2006. This standard provides derating requirements for electronic, electrical and electromechanical components used for space projects and applications.

Once a derating standard has been applied, you will need to define the derating properties of each component that will be analyzed. The application will then automatically evaluate each component to determine whether it meets the derating requirements provided by the standard you are working with. Any components of types not specified in the derating standard are not considered in the derating analysis.