Physical property damage isn't a requirement of the definition of 'hard real time', it's just that common examples are often given that way. If deadlines are m

Physical property damage isn't a requirement of the definition of 'hard real time', it's just that common examples are often given that way. If deadlines are missed in multimedia applications the product isn't meeting its stated and implied requirements. The consequences may be different, but a television that drops perceptible video frames is just as 'defective' (from an engineering point of view) as an industrial control system which drops motor control signals.