Pan-STARRS is a tool for quickly surveying large areas of sky to faint limits.For many applications the rate at which objects can be detected scales as the entendue of the telescope, which is defined as the product of its collecting area (A) times the field of view (Ω).
The best existing survey instruments are Subaru and Gemini, which have (AΩ) of about 14 m2 deg2. Pan-STARRS will have a (AΩ) of 54 m2 deg2, about three times better.