I'm trying to solve a transportation cost problem using simplex tableu and the stepping stone algorithm.
I've done one iteration using the minimum cost method and this is the tableu I have obtained:
From here I've used the stepping stone algorithm and found that we could lower the cost even more if we increase the flow to $CW$.
The stepping stone algorithm showed that $CW = 3+3-3-4 = -1$ which shows cost could be lowered.
Where I'm confused is how much I should increase the flow in $CW$ by. In the solutions to the question I can see that apparently the max we can increase the flow by is $2$ but I'm not shown how this was obtained/decided.
If someone could show me how we decide the maximum we can increase the flow by it would really help since I will need to do more iterations of the stepping stone algorithm to find the optimal solution.
Thanks in advance