%0 Book Section %T Formal testing of systems presenting soft and hard deadlines publisher SPRINGER-VERLAG BERLIN %D 2007 %U 978-3-540-75697-2 %@ https://hdl.handle.net/20.500.14352/53128 %X We present a formal framework to specify and test systems presenting both soft and hard deadlines. While hard deadlines must be always met on time, soft deadlines can be sometimes met in a different time, usually higher, from the specified one. It is this characteristic (to formally define sometimes) what produces several reasonable alternatives to define appropriate implementation relations, that is, relations to decide wether an implementation is correct with respect to a specification. In addition to introduce these relations, we define a testing framework to test implementations. %~