Research Article

Intelligent Optimization Algorithms: A Stochastic Closed-Loop Supply Chain Network Problem Involving Oligopolistic Competition for Multiproducts and Their Product Flow Routings

Table 4

Comparison of the optimal strategies obtained by PSO algorithm and GA in the reverse logistics of Example 2.

PSO GA
MeanStdev. MeanStdev.

Firm 1Optimal percentage of product 1 returning from demand market to firm 1 via recovery center 0.5709 0.0269 0.5151 0.0110
0.5927 0.0250 0.5211 0.0226
0.6977 0.0224 0.6428 0.0145
Optimal percentage of product 2 returning from demand market to firm 1 via recovery center 0.5790 0.0317 0.5413 0.0043
0.6262 0.0218 0.6666 0.0135
0.7497 0.0204 0.7562 0.0134

Firm 2Optimal percentage of product 1 returning from demand market to firm 2 via recovery center 0.4084 0.0352 0.4199 0.0152
0.5694 0.0244 0.5242 0.0190
0.5859 0.0313 0.5452 0.0180
Optimal percentage of product 2 returning from demand market to firm 2 via recovery center 0.4000 0.0326 0.3517 0.0158
0.5401 0.0231 0.5403 0.0182
0.6085 0.0366 0.6510 0.0066

Firm 3Optimal percentage of product 1 returning from demand market to firm 3 via recovery center 0.3107 0.0235 0.3166 0.0080
0.4213 0.0175 0.4384 0.0138
0.5590 0.03170.5069 0.0249
Optimal percentage of product 2 returning from demand market to firm 3 via recovery center 0.2819 0.0215 0.2287 0.0071
0.3262 0.0318 0.3523 0.0152
0.5463 0.0176 0.5463 0.0229

Firm 4Optimal percentage of product 1 returning from demand market to firm 4 via recovery center 0.2110 0.0315 0.2177 0.0143
0.3224 0.0293 0.3159 0.0152
0.4405 0.0297 0.4358 0.0094
Optimal percentage of product 2 returning from demand market to firm 4 via recovery center 0.1726 0.0214 0.1219 0.0080
0.2561 0.0221 0.2699 0.0220
0.3390 0.0334 0.3169 0.0162

Note: optimal percentage of product returning from demand market to firm via recovery center  − optimal percentage of product returning from demand market to firm via recovery center (, , and ).