Hi Anurag,
in the table V_554S_O suggested by Amit, click on the field Time cstr. class Press F1 then you will get the below information
i believe you wanted to make it as over write when the collision occurs between 2001 & 2002 if that is the case then please refer to the below information
Time constraint class
The time constraint class is used to check for collisions between Time Management infotypes (2001 to 2012).
It allows you to specify different regulations for checking for collisions between individual subtypes
Time Constraint Reaction to Time Management Infotypes (V_554Y_B)
Global Time Constraint Reaction (V_T554Y) contain rules for the collision check
regards
Rahul