Many industrial experiments have shown that the very simple and time-efficient Scan test detects many unique faults. This paper shines a new light on the properties of Scan test; such properties will be evaluated using industrial data. In addition, it will be shown that many faults in a memory, which are not in the cell array, are detectable using the appropriate read-write sequences. The traditional version of Scan test performs "some" of such read-write sequences, but lacks the capability of performing all of them for both the "up" and the "down" address orders and the "0" and the "1" data values. Therefore a new set of Scan based tests will be proposed to fill that vacuum.