Description: Probability of an object's suitability when required to be in a working condition under given conditions at a given time and assuming the necessary external resources are provided; Name: immediate availability
Description: Probability that an item is in a state to perform as required at a given instant, under given conditions, assuming that the necessary external resources are provided ; Name: Instantaneous availability
Description: pressure at the input of a device or a plant which is needed so that the device or the plant works according to design; Name: required supply pressure