Hi,

let us go on with https://www.linkedin.com/pulse/making-decision-optimization-simple-alex-fleischer/

But now suppose we do not need only the optimal solution but a few alternatives to share.

Solution pools!

Let me share a tiny example:

int nbKids=300;
float costBus40=500;
float costBus30=400;
 
dvar int+ nbBus40;
dvar int+ nbBus30;
 
minimize
 costBus40*nbBus40  +nbBus30*costBus30;
 
subject to
{
 40*nbBus40+nbBus30*30>=nbKids;
}

execute
{
writeln("nbBus40 = ",nbBus40," and nbBus30 = ",nbBus30," and the cost is ",costBus40*nbBus40  +nbBus30*costBus30);
}

 main {
cplex.solnpoolintensity=2;

    thisOplModel.generate();
    cplex.solve();
    if (cplex.populate()) {
      var nsolns = cplex.solnPoolNsolns;
      
      
      writeln("Number of solutions found = ",nsolns);
      writeln();
      for (var s=0; s<nsolns; s++) {
        thisOplModel.setPoolSolution(s);
        thisOplModel.postProcess();
      }
    }
}

which gives

Number of solutions found = 3

nbBus40 = 6 and nbBus30 = 2 and the cost is 3800
nbBus40 = 7 and nbBus30 = 1 and the cost is 3900
nbBus40 = 8 and nbBus30 = 0 and the cost is 4000

regards

Alex Fleischer

PS:

Many how to with OPL at https://www.linkedin.com/pulse/how-opl-alex-fleischer/

Many examples from a very good book : https://www.linkedin.com/pulse/model-building-oplcplex-alex-fleischer/

Making optimization simple : https://www.linkedin.com/pulse/making-decision-optimization-simple-alex-fleischer/