Network Simplex - Evaluating a Nonbasic Arc Previous Next
Suppose arc DF with flow  is added to the feasible spanning tree. The unique undirected cycle in this case is DF-FC-CB-BD. The above network shows next to each arc the resulting incremental flow (in parentheses) and the cost per unit flow (to the left of the parentheses).
When , the resulting overall increment in total cost () is
  = 4(1) + 2(-1) + 2(-1) + 3(1) = 3.
Hence, the rate of change of  as  is increased is 3.