Hello Krish,
First off, you must understand why one would use a Location Heuristic. This heuristic is useful if you would like to have control over which plants are planned during the heuristic execution. For instance, if you have a situation where Product A is planned at plants P1 and P2, which is in turn supplied by P3, a location Heuristic would have to be executed at each of the plants in order (P1 and P2 first and then P3). You could define a Location Heursitic schedule to run for the plants at say, different times, and then finally execute a Location Heuristic at P3 once all the demand is available. In comparison, a network Heuristic for Product A would plan at all three locations, in order, without really giving you an option to exclude a plant.
I hope this helps.
Thanks and Regards,
Sharath