North West Corner Rule:
Step1: The first assignment is made in the cell occupying the upper left hand ( north west ) corner of the transportation table. The maximum possible amount is allocated there. That is X_{11} min ( aa1 , b1) this value of X_{11} is then entered in the cell ( 1, 1) of the transportation table.
Step 2 :
a. If b1> a_{1} move vertically downwards to the second row and make the second allocation of amount X_{21} = min ( a_{1} b_{1}- X_{11}) in the cell ( 2,1,).
b. If b_{1} < a_{1} move horizontally right side to the second column and make the second allocation of amount X_{12} min ( a_{1}- X_{11 }, b_{2} ) in the cell (1,2).
c. If b_{1} = a_{1} there is a tie for the second allocation . one can make the second allocation of magnitude X_{12 }= min ( a_{1}- a_{1}, b_{2} ) = 0 in the cell ( 1,2) or X21 = min ( a_{2} b_{1}- b_{1}) = o in the cell ( 2,1)
Step 3: Start from the new north west corner of the transportation table and repeat steps 1 an d2 until all the requirements are satisfied.