Least Cost Methods ( LCM): The NW corner rule describe earlier consider only the availability and supply requirements in making assignments'. It take no according of the shipping costs given in the tableau. It is therefore not a sound method as it ignores the very factor ( cost) which is sought to be minimized. The least cost method and the Vogel Approximation methods consider the shipping costs while making allocations.
The transportation schedule obtained is reproduced in table below. It involves a total cost of Rs. 555. Total Cost 4x15+1x35+3x20+8x20+4x60x= Rs. 555