This global standard was actually founded by the automotive industry leaders of Chrysler , GM , and Ford. They were in a meeting to discuss JEDEC standards in 1993 and decided the automotive industry needed components to meet the requirements to work within the harsh environments of vehicles. The following year they officially started a committee and started developing the standards that are required today. They developed ways to see how much stress the parts can take and if it can stand to be used within the automotive environments such as extreme heat or cold ,vibration , etc. The AEC-Q200 automotive grade is for all makes and models of vehicles across the industry. The automotive grade rating is not just for a particular type , they all worked together to have the same standards .
The components made by the manufacturers have to go through certain testing to qualify for the AEC-Q200 grade rating. The manufacturer must provide a test batch of components along with the correct information . For example : size, composition , values , temperature rating, etc. The testing can now be conducted to see if the part does in fact hold up to what the manufacturer has said that is supposed to. The test results will be based on consistency, failures , and reliability.
There is also several levels within a grade , for example temperature ratings on capacitors, inductors or other passive components. The industry has different needs of temperatures so they are all tested at the higher or lower levels . The trials the components are put through will have pre and post stress tests . In addition,because of the testing there is a higher cost for the component, but you will end up with a reliable part that is proven to work how it was made to. The following link will show how the tests are conducted along with other standards AEC provides : http://www.aecouncil.com/AECDocuments.html