Specifications often state that a certain incident or event should not occur more than, say, once in 1 million or once in 10 million times. Explain why tests to ensure such a requirement are difficult and costly.

Insufficient quality management during product development, launch, and production can lead to subsequent costly projects and programs to rectify problems. This is especially true when safetycritical items are involved. The 2015 global recall of a large variety of automobile makes, which affected millions of owners, is such as case. The massive recall was related to potentially defective airbags used by auto manufacturers following reports that the airbags had inflators that could explode and expel metal and plastic shards into vehicle occupants. The airbags were supplied by Takata Corporation of Japan, the second largest global supplier of airbags and seatbelts. A New York Times report found a total of at least 139 reported injuries across all automakers; in Honda vehicles alone, at least two deaths and 30 injuries were reported.