In which situation we will go ahead with SEQUENCE object instead of IDENTITY Column?

Answer:

A SEQUENCE object can be used instead of the IDENTITY column in the following scenarios:
1) The application requires the value before an INSERT statement is executed.
2)The application requires the values to be shared between two or more tables.
3) The application has to restart the sequence after a certain value has been
reached.
4) The application requires sequence values to be sorted by another column