Resources

Model Construction (omod3)

/***************************************************************/
/*                                                             */
/*          S A S   S A M P L E   L I B R A R Y                */
/*                                                             */
/*    NAME: omod3                                              */
/*   TITLE: Model Construction (omod3)                         */
/* PRODUCT: OR                                                 */
/*  SYSTEM: ALL                                                */
/*    KEYS: OR                                                 */
/*   PROCS: OPTMODEL, TABULATE                                 */
/*    DATA:                                                    */
/*                                                             */
/* SUPPORT:                             UPDATE:                */
/*     REF:                                                    */
/*    MISC: Example 3 from the OPTMODEL chapter of             */
/*          Mathematical Programming.                          */
/*                                                             */
/***************************************************************/

title 'An Assignment Problem';

data grade(drop=i);
   do i = 1 to 6;
      grade = 'grade'||put(i,1.);
      output;
   end;
run;


data object;
   input machine customer
         grade1 grade2 grade3 grade4 grade5 grade6;
   datalines;
1 1 102 140 105 105 125 148
1 2 115 133 118 118 143 166
1 3  70 108  83  83  88  86
1 4  79 117  87  87 107 105
1 5  77 115  90  90 105 148
2 1 123 150 125 124 154   .
2 2 130 157 132 131 166   .
2 3 103 130 115 114 129   .
2 4 101 128 108 107 137   .
2 5 118 145 130 129 154   .
3 1  83   .   .  97 122 147
3 2 119   .   . 133 163 180
3 3  67   .   .  91 101 101
3 4  85   .   . 104 129 129
3 5  90   .   . 114 134 179
4 1 108 121  79   . 112 132
4 2 121 132  92   . 130 150
4 3  78  91  59   .  77  72
4 4 100 113  76   . 109 104
4 5  96 109  77   . 105 145
;


data demand;
   input customer
         grade1 grade2 grade3 grade4 grade5 grade6;
   datalines;
1 100 100 150  150  175  250
2 300 125 300  275  310  325
3 400   0 400  500  340    0
4 250   0 750  750    0    0
5   0 600 300    0  210  360
;


data resource;
   input machine
         grade1 grade2 grade3 grade4 grade5 grade6 avail;
   datalines;
1 .250 .275 .300  .350  .310  .295  744
2 .300 .300 .305  .315  .320  .     244
3 .350 .    .     .320  .315  .300  790
4 .280 .275 .260  .     .250  .295  672
;


proc optmodel;
   /* declare index sets */
   set CUSTOMERS;
   set <str> GRADES;
   set MACHINES;

   /* declare parameters */
   num return {CUSTOMERS, GRADES, MACHINES} init 0;
   num demand {CUSTOMERS, GRADES};
   num cost {GRADES, MACHINES} init 0;
   num avail {MACHINES};

   /* read the set of grades */
   read data grade into GRADES=[grade];

   /* read the set of customers and their demands */
   read data demand
      into CUSTOMERS=[customer]
      {j in GRADES} <demand[customer,j]=col(j)>;

   /* read the set of machines, costs, and availability */
   read data resource nomiss
      into MACHINES=[machine]
      {j in GRADES} <cost[j,machine]=col(j)>
      avail;

   /* read objective data */
   read data object nomiss
      into [machine customer]
      {j in GRADES} <return[customer,j,machine]=col(j)>;

   /* declare the model */
   var AmountProduced {CUSTOMERS, GRADES, MACHINES} >= 0;
   max TotalReturn = sum {i in CUSTOMERS, j in GRADES, k in MACHINES}
      return[i,j,k] * AmountProduced[i,j,k];
   con req_demand {i in CUSTOMERS, j in GRADES}:
      sum {k in MACHINES} AmountProduced[i,j,k] = demand[i,j];
   con req_avail {k in MACHINES}:
      sum {i in CUSTOMERS, j in GRADES}
         cost[j,k] * AmountProduced[i,j,k] <= avail[k];

   /* call the solver and save the results */
   solve;
   create data solution
      from [customer grade machine] = {i in CUSTOMERS, j in GRADES,
         k in MACHINES: AmountProduced[i,j,k].sol ne 0}
      amount=AmountProduced;

   /* print optimal solution */
   print AmountProduced;
quit;

proc tabulate data=solution;
   class customer grade machine;
   var   amount;
   table (machine*customer), (grade*amount=''*sum='');
run;