Description: probability for an item to be in a state to perform as required at a given instant; 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: determined through a surface, product of the sound pressure, p, and the component of the particle velocity, un, at a point on the surface in the direction normal to the surface, integrated over that surface; Name: sound power