set default
set echoin 1
 MODEL:
! A 3 Warehouse, 4 Customer
   Transportation Problem;
SETS:
   WAREHOUSE / WH1, WH2, WH3/   : CAPACITY;
   CUSTOMER   / C1, C2, C3, C4/ : DEMAND;
   ROUTES( WAREHOUSE, CUSTOMER) : COST, VOLUME;
ENDSETS

! The objective;
 [OBJ] min = @SUM( ROUTES: COST * VOLUME);

! The demand constraints;
 @FOR( CUSTOMER( J): [DEM]
  @SUM( WAREHOUSE( I): VOLUME( I, J)) >=
   DEMAND( J));

! The supply constraints;
 @FOR( WAREHOUSE( I): [SUP]
  @SUM( CUSTOMER( J): VOLUME( I, J)) <=
   CAPACITY( I));

! Here are the parameters;
DATA:
   CAPACITY =   30, 25, 21 ;
   DEMAND =   15, 17, 22, 12;
   COST =      6,  2,  6,  7,
               4,  9,  5,  3,
               8,  8,  1,  5;
ENDDATA
END
set terseo 1
go
nonz volume
quit