Research Article

Exact and Heuristic Solutions to Minimize Total Waiting Time in the Blood Products Distribution Problem

Algorithm 4

The outline of hybrid algorithm.
Initial procedure GRASP, report the best found solution 𝑥 ;
Initial procedure SA + VNS;
Repeat
Local search: apply VNS procedure with the five neighborhoods, report the incumbent
solution ́ 𝑥 ;
Calculate Δ ;
If Δ < 0 then 𝑥 ́ 𝑥 ;
Elseif random(0,1) < 𝑒 Δ / 𝑇 , then 𝑥 ́ 𝑥 ;
Else Reject ́ 𝑥 , and modify temperature;
Until stopping criterion is met;