Assignment_1.mos

model Assignement_1
uses "mmxprs"; 

declarations
! Define the Parameters
  FactoryNames: set of integer
  Warehouse: set of string
  Distance: array(FactoryNames, Warehouse) of integer
  Demand: array(Warehouse) of integer
  Capacity: array(FactoryNames) of integer
  b: integer
  M: integer
  b_discount: real
  FixedCost: real
  FixedSavings: array(FactoryNames) of integer
end-declarations

initializations from "data.dat"
	FactoryNames Warehouse Distance Demand Capacity FixedCost b M FixedSavings b_discount
end-initializations

declarations
! Define the Variables of the problem
  Units: array(FactoryNames, Warehouse) of mpvar
  Factory:array(FactoryNames) of mpvar
  Sent:array(FactoryNames, Warehouse) of mpvar
end-declarations

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!! Define used procedures !!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

!forward procedure reportCSV 
forward procedure print_status 
forward procedure reportCSV

! Set the ExcelOutput to true in order to output a CSV file

ExcelOutput := false
ExcelFile := "Supply.csv"


!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!! Define the operational constraints !!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

! Demand must be met
forall ( j in Warehouse) do
	DemandCS(j) :=  sum( i in FactoryNames ) Units(i, j) >= Demand(j)
end-do


! Capacity must not be exceeded
forall ( i in FactoryNames) do
	CapacityCS(i) :=  sum( j in Warehouse ) Units(i, j) <= Capacity(i)
end-do

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!! State the objective functions for all scenarios!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

!
! Intitial Agreement
!
Cost := sum(i in FactoryNames,j in Warehouse) b * Distance(i,j) * Units(i,j)	
minimize(Cost)
writeln("Intitial Agreement")
writeln("==================")
print_status
reportCSV

!
! Ammended agreement
!
forall ( f in FactoryNames, w in Warehouse) do 
	Sent(f,w) is_binary
	Units(f,w) <= Sent(f,w) * M
end-do

Cost := sum(i in FactoryNames,j in Warehouse) (b * b_discount * Distance(i,j) * Units(i,j) + FixedCost * Sent(i,j))

minimize(Cost)

writeln
writeln
writeln("Ammended Agreement")
writeln("==================")
print_status
reportCSV

! Closing down factories

forall ( f in FactoryNames) do 
	Factory(f) is_binary
end-do

! Demand must be met
forall ( j in Warehouse) do
	DemandCS(j) :=  sum( i in FactoryNames )  Units(i, j) >= Demand(j)
end-do



! Capacity must not be exceeded
forall ( i in FactoryNames) do
	CapacityCS(i) :=  sum( j in Warehouse )  Units(i, j) <= Capacity(i) * Factory(i)
end-do

Cost := sum(i in FactoryNames,j in Warehouse) b * Distance(i,j) * Units(i,j) - sum(i in FactoryNames)  FixedSavings(i) * (1-Factory(i))
minimize(Cost)

writeln
writeln
writeln("Option to close a factory")
writeln("=========================")
print_status
reportCSV




!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
! Procedures defined in this model !
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

! Procedure to print final status of problem
procedure print_status
 declarations
  status: string
 end-declarations

 case getprobstat of
  XPRS_OPT: status:="Optimum found"
  XPRS_UNF: status:="Unfinished"
  XPRS_INF: status:="Infeasible"
  XPRS_UNB: status:="Unbounded"
  XPRS_OTH: status:="Failed"
  else status:="???"
 end-case

writeln("Problem status: ", status)
 if ExcelOutput then
 	writeln("CSV file written to disk")
 end-if
 
end-procedure


! Procedure to append output to a CSV file
procedure reportCSV
	writeln
		if ExcelOutput	then
			fopen(ExcelFile, F_APPEND)
			write(",")
			forall( j in Warehouse) do
				write(Warehouse(j), ",")
			end-do
			
			writeln
				
			forall ( i in FactoryNames) do
					write(i,",")
					forall( j in Warehouse) do
						write(getsol(Units(i,j)), "," )
					end-do
					writeln
			end-do
			
			writeln("Total Costs,", getsol(Cost))
			fclose(F_APPEND)
			
			else
				write("  ")
				forall( j in Warehouse) do
				write(Warehouse(j), " ")
				end-do
			
				writeln
				
				forall ( i in FactoryNames) do
					write(i," ")
						forall( j in Warehouse) do
							write(getsol(Units(i,j)), " " )
						end-do
						writeln
				end-do
				writeln
				writeln("Total Costs:= ", getsol(Cost))
			end-if
			
end-procedure

end-model