Originally posted by: LeandroCC

If I am able to tell CPLEX the value of a variable in the optimal solution, should I add a new constraint (model.add(var == value)), or use setBounds (var.setBounds(value,value))?

Is there any difference between these two approaches? If so, in which case one is preferred over the other?

The differences between the two approaches are rather minor, the slightly better one is to explicitly fix the variable using setBounds().