4.1. The branching number
This index means the branching number of B&B tree before terminating B&B procedure.
The results of branching number are shown in Table 2.
Our method is compared with original B&B method for ILP problems with m constraints and n variables.
Intuitively speaking, the complicated or large-size problems should need more branching operations, especially with many variables and constraints.
However, the numerical results show that they are almost the same for B&B and our method except the case of m = 8 and n = 2.
This is because the eliminated solution space is also ignored during B&B procedure.
Moreover, if the optimum point is not found in the first subspace, it needs to use B&B procedure twice.