When a point is created with no value against it, its default value is in different format and If value is set against that point, it gets stored as per point type .Can you please let us known why are point's default values not as per point type?

There are many reasons why a SYSTEM state is used rather than the default for the point type. First and foremost of all, it is because that is both a long and well established standard of the realm of Process Controls. These standards were in place well before the first ever PI Server was created.

Another reason is that the default for numeric types is 0, which does not tell you much. In fact, you must also look at the quality properties to ensure the state is bad and not a legitimate 0. And even with the tandem pair of a 0 and a bad quality value, you still no little. Compare that to states such as "Pt Created", "Scan Off", "Arc Offline", "Under Range", "Over Range", etc. I see those states and immediately know the value is bad without looking at other properties. And they tell me a little something about WHY it is bad.