A Hybrid Multiobjective Evolutionary Approach for Flexible Job-Shop Scheduling Problems

Algorithm 1

Pseudocode of decoding procedure.

Beginning Decoding Procedure

initialize vector of machines availabilities Dispo_Machine[k]=0 for each

machine 𝑀_𝑘(𝑘≤𝑀);

initialize vector of idle intervals Interval_Machine[k][m]=0 for each ma-

chine 𝑀_𝑘(𝑘≤𝑀);

initialize vector of jobs availabilities Dispo_Job[j]=0 for each job 𝑗(𝑘≤𝑁);

for   𝑖=1 to 𝑂 (𝑂 is the length of chromosome) do

 Schedule operations 𝐼_𝑖(1≤𝑖≤𝑂) from left to right.

 Search an available idle interval from left to right on machine 𝑘 for

 operation 𝐼_𝑖.

 if Such an interval exists. then

  Insert the operation into that interval.

  Update Interval_Machine[k][m].

 else

  Determine 𝑡=max{Dispo_Machine [𝑘],  Dispo_Job [𝑗]}.

  Set the start time of operation 𝐼_𝑖 as 𝑡.

  Update Dispo_Machine[k].

  Update Interval_Machine[𝑘][𝑚].

  Update Interval_Machine[k][m].

 end if

end for