production.pi

/* 

  Production-planning in Picat.

  From the OPL model production.mod.

  This Picat model was created by Hakan Kjellerstrand, hakank@gmail.com
  See also my Picat page: http://www.hakank.org/picat/

*/


import mip.


main => go.


go =>
  
  Products = [kluski, capellini, fettucine],
  NumProducts = Products.length,
  Resources = [flour, eggs],
  % Consumption[Products, Resources]
  Consumption = [ 
                   [0.5, 0.2], 
                   [0.4, 0.4], 
                   [0.3, 0.6] ],
  Capacity = [ 20, 40 ],
  Demand = [ 100, 200, 300 ],
  InsideCost = [0.6, 0.8, 0.3 ],
  OutsideCost = [0.8, 0.9, 0.4],

  % decision variables
  Inside = new_list(NumProducts),
  Outside = new_list(NumProducts),

  Z #= sum([InsideCost[P]*Inside[P] + OutsideCost[P] * Outside[P] :  P in 1..NumProducts]),
    
  foreach(R in 1..Resources.length)
    sum([Consumption[P,R]*Inside[P] : P in 1..NumProducts]) #<= Capacity[R]
  end,

  foreach(P in 1..NumProducts)
    Inside[P] + Outside[P] #>= Demand[P]
  end,

  solve($[min(Z)], Inside ++ Outside),

  println(z=Z),
  println(inside=Inside),
  println(outside=Outside),

  nl.