maximize

OPL keyword for the objective function

Purpose

OPL keyword to express the objective function.

context
Model files (.mod)

Syntax

Objective: . "minimize" Expression
         | . "maximize" Expression

Description

OPL instructions are responsible for stating the problem constraints and, in optimization problems, the objective function. Constraints are stated in OPL by an optimization instruction: maximize or minimize.

Note:

  1. Optimization instructions require an objective function of type integer or float.

  2. You cannot insert an execute block between a maximize or minimize statement and constraint definitions. If there are no constraints for an objective definition, use an empty one like “subject to {}” instead.

Example

{string} Products = { "Car", "Truck"};
{string} Components = { "Wheel", "Tyre"};
float demand[Products][Components] = [[ 100, 200] ,[300 ,400]];
float profit[Products] = [20 ,50];
float stock[Components] = [2000 ,4000];

dvar float+ production[Products];
maximize
  sum (p in Products) profit[p] * production[p];
subject to {
  forall (c in Components)
    sum (p in Products) demand[p, c] * production[p] <= stock[c];
}