Effects of Integration on the Cost Reduction in Distribution Network Design for Perishable Products

Table 2

Lagrangian relaxation parameters.

Parameters	15-node	49-node
Maximum iterations	500	1500
Number of nonimproving iterations before halving step size	30	30
Initial value of step size	2	2
Minimum value of step size	10^−7	10^−7
Initial value of Lagrangian multiplier	10(𝑑+𝑓)	10(𝑑+𝑓)
Maximum optimality gap ((UB−LB)/UB)∗100%	0.1%	0.1%

𝑑,𝑓 are, respectively, the average demands of retailer and the average fixed installation costs of the DCs.