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 𝑥́;

  Calculate Δ;

   If Δ < 0 then 𝑥←𝑥́;

   Elseif random(0,1) < 𝑒^−Δ/𝑇, then 𝑥←𝑥́;

   Else Reject 𝑥́, and modify temperature;

 Until stopping criterion is met;