Dear Altruist,
I'm using IBM CPLEX for the cost optimization modeling of a multi echelon supply chain design network .
My modeling code is like as below -
//indices
{string} Components = ...; //u
{string}Suppliers = ...; //j
{string} Assemblers =...; //k
{string} Periods =...;//t
//Parameters
float FixCost[Components]=...;
int Distance[Suppliers][Assemblers]=...;
float HoldCost[Components][Assemblers]=...;
float Capacity [Components][Suppliers]=...;
int MaxHold [Components][Assemblers][Periods]=...;
int SetCost[Suppliers]=...;
float SellingPrice[Components][Suppliers]=...;
int InvComp [Components][Assemblers][Periods];
int OrderComp[Components][Suppliers][Assemblers];
// decision variables
//dvar float InvComp [Components][Assemblers][Periods];
//dvar float OrderComp[Components][Suppliers][Assemblers][Periods];
dvar boolean y [Suppliers][Assemblers][Periods];
// Objective Function
dexpr float TotalCost = sum(t in Periods, j in Suppliers , k in Assemblers, u in Components)FixCost[u]*Distance[j][k]*OrderComp[u][j][k]
+ sum(t in Periods,k in Assemblers,u in Components)HoldCost[u][k]*InvComp[u][k][t]
+ sum(t in Periods,k in Assemblers,j in Suppliers)SetCost[j]*y[j][k][t]
+ sum(t in Periods,k in Assemblers, j in Suppliers, u in Components)SellingPrice[u][j]*OrderComp[u][j][k];
minimize TotalCost;
subject to{
forall(u in Components,k in Assemblers,t in Periods)
InvComp[u][k][t] <= MaxHold[u][k][t];
forall (u in Components,j in Suppliers,t in Periods)
sum(k in Assemblers)OrderComp[u][j][k] <= Capacity[u][j] ;
}
My dat file is like -
Components = {First Second Third}; //u
Suppliers = {First Second Third}; //j
Assemblers ={First Second Third}; //k
Periods = {First Second Third}; //t
FixCost = [0.06 ,0.08, 0.09]; //DelU
Distance = [[40, 35, 25],
[50, 60, 40],
[45, 45, 30]]; //CC_jk
//OrderComp= [[300, 200, 100, 115, 150, 160, 150, 145, 140],
//[120, 130, 140, 110 ,125, 135, 130, 145, 160],
// [160, 150, 110, 140, 135, 160, 115, 120, 135]]; //Z_ujkt
HoldCost = [ [1, 1.5, 2],[ 2, 2, 2.5], [1, 1, 2]]; // hu_uk
//InvComp= [[300, 200, 100, 115, 150, 160, 150, 145, 140],
//[120, 130, 140, 110, 125, 135, 130, 145, 160],
//[160, 150, 110, 140, 135, 160, 115, 120, 135]]; // IU_ukt
SetCost = [ 100, 200, 150]; //O_j
SellingPrice = [[10, 30, 18]
[15, 35, 20],
[20, 25, 15]]; // S_uj
Capacity = [[1000,1500,4000],
[2000,3000,2000],
[3000, 3500, 3000]];// CS-uj
MaxHold = [[110 ,200, 100], [115, 150, 160], [150, 145, 140], [120, 130, 140], [110, 125, 135],[130, 145, 160],
[160, 150, 110],[140, 135, 160],[115, 120, 135]]; //MI_UKT
While running the model I'm getting output that says "unexpected data item error. Would anyone suggest me how to get rid off that . Thanks in advance
------------------------------
Md Ashikur Rahman
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#DecisionOptimization