Originally posted by: JamesGordon16549879

Hello !

i am using the goal programing aproach to solve  my  multi objectif  problem ,   the issus is that how can  i maximize vf1 and vf3 and minimize  vf2 in the same time ? 

dvar int vf1;
dvar float vf2;
dvar int vf3;

maximize (vf1+vf2+vf3); 

subject to {

vf1 == sum (p in patient, i in jours,h in plage)Y[p][i][h]; 
vf2 == sum (p in patient , m in medcin) Dpm[p][m]*Z[p][m];
vf3 == sum (p in patient)O[p]; 

-------------------------

main script // 

Opl.generate();
Cplex.setObjCoef(Opl.vf2, 0);
Cplex.setObjCoef(Opl.vf3, 0);
Cplex.solve();
   Opl.postProcess();
var f1=Opl.vf1.solutionValue;
   Opl.vf1.LB=f1;
   Opl.vf1.UB=f1;
   Cplex.setObjCoef(Opl.vf2,+1);
   Cplex.solve();
 Opl.postProcess(); 
  Opl.generate();
   Cplex.setObjCoef(Opl.vf1,0);
   Cplex.setObjCoef(Opl.vf3,1); 
   Cplex.solve();
   Opl.postProcess();
   var f3=Opl.vf3.solutionValue;
   Opl.vf3.LB=f3;
   Opl.vf3.UB=f3;
   Cplex.setObjCoef(Opl.vf1,1);
   Cplex.solve();
   Opl.postProcess(); 

 thanks , regards ! 

Originally posted by: open_ball

Hi,

I answered a similar question here https://www.ibm.com/developerworks/community/forums/html/topic?id=35a82d41-cac3-4cd5-8b5d-76b7c91769a3

Hope this helps.

Originally posted by: JamesGordon16549879

Hey thanks  for replying ,

 Then i should change this sentence :

Opl.vf1.UB=f1;
   Cplex.setObjCoef(Opl.vf2,+1);
   Cplex.solve();

INTO :

 Opl.vf1.UB=f1;
   Cplex.setObjCoef(Opl.vf2,-1);
   Cplex.solve();

 Thanks a lot !

regards .