Variable Neighborhood Search for Parallel Machines Scheduling Problem with Step Deteriorating Jobs

Algorithm 5

Procedure of the proposed VNS algorithm.

Procedure: the proposed VNS algorithm

Initialization: Define the set of neighborhood structures 𝑁𝑆𝑆_𝑘, for 𝑘=1,…, 𝑘_max;

      find a initial solution 𝑥 by SRF heuristic;

      choose a stopping criterion.

𝑘=1

while the stopping criterion is not met do

 perform the neighborhood search structure 𝑁𝑆𝑆_𝑘

 if  x is improved do

  continue the search with 𝑁𝑆𝑆_𝑘

 else

  k = k mod 𝑘_max+1

 end  if

end  while