Difficulty arise when if all uncrossed out rows or column have (remaining) zero supply or demand. In that case, Vogel‟s Approximation Method (VAM) and some other methods solve that by allocating these zero supply or demand using Least Cost Method (LCM). But in some problem when we make allocation by LCM in that particular case then closed loop is formed and not possible to apply any optimality test method. So that optimal solution is not possible to determine in that case