! Keywords: Break Even Point / Inventory / Marketing / Product Management / Product Mix / Production / Sales;
! Maximize revenue minus costs;
 MAX   3 A  + 3 B  + 3 C + 3 D + 2 D2 + 3 E + 2 E2 
     - 4 M1 - 4 M2 - 3 M3
SUBJECT TO
! Machine time used = machine time made available;
   2)  12 A +  7 B   + 8 C + 10 D + 10 D2 
      + 7 E +  7 E2 - 60 M1 = 0
   3)   8 A +  9 B   + 4 C + 11E + 11 E2 - 60 M2 = 0
   4)   5 A + 10 B  + 7 C +  3 D +  3 D2 
      + 2 E + 2 E2 - 60 M3 = 0
! Product limits;
   5)  D <= 20
   6)  E <= 20
! Machine availability;
   7)  M1 <= 128
   8)  M2 <= 128
   9)  M3 <= 128
END