How do I fix the error for my code CPLEX?

Question

I have some problem with my code. VC must add X(i)(j)(k) but when multiplying and running the result, there is a problem of splitting the route and not starting from the depot. Can "execute" be used for additional calculation for "objective function"? If not, how should I fix the code? I am working on the multi-depot VRP problem including 2 depots, 7 customers, and 1 type of vehicle.

//Parameters

int numOfN = ...; 

int numOfM = ...; 

int numOfK = ...; 

int numOfL = ...; 

int Mdist = ...; 

int numOfP = numOfN + numOfM; 



range P = 1..numOfP; 


range I = 1..numOfM; 

range J = numOfM+1..numOfM+numOfN; 



range K = 1..numOfK;  

range L = 1..numOfL; 



float dist_ij[P, P] = ...; 

float veh_k_Cap[1..numOfK] = ...; 

float veh_k_FC[1..numOfK] = ...; 

float veh_k_VC[1..numOfK] = ...; 

float veh_k_DC[1..numOfK] = ...; 



float item_l_W[1..numOfL] = ...; 



float demand_il[P, L] = ...; 



// Decision variable 



dvar boolean X[P][P][K]; 

dvar int+ D[P][K][L]; 

dvar int+ S[P][P][K][L]; 





 //Objective function 

 minimize 

sum(i in P, j in P, k in K: i!=j) veh_k_FC[k]*X[i][j][k] 

+ sum(i in P, j in P: i!=j) dist_ij[i][j] * sum(k in K) veh_k_VC[k] 

+ sum(i in J, j in J, k in K: i!=j) veh_k_DC[k]*X[i][j][k]; 

 // --------------------------------------------- 

 subject to { 

  // (2) Each order can be divided into multiple trips. 

   forall(j in P) 

   sum(i in P, k in K: i!=j) X[i][j][k] >= 1; 

 // (3) The number of vehicles arriving at a destination is equal to the number of vehicles leaving 

  forall(k in K, p in P) 

  sum(i in P) X[i][p][k] - sum(j in P) X[p][j][k] == 0; 

// (4) Each vehicle can only visit a delivery point once. 

  forall(k in K, i in J: i>1) 

 sum(j in P) X[i][j][k] <= 1; 

// (5) Each vehicle can only travel from the construction material store once. 

 forall(k in K, i in I: i>1) 

  sum(j in P) X[i][j][k] <= 1; 

// (6) Each vehicle can only travel to the depot once

 forall(k in K, i in I) 

 sum(j in P) X[j][i][k] <= 1; 

// (7) The delivery route of each vehicle cannot exceed the maximum distance required.

 forall(k in K)  

 sum(i in P, j in P: i!=j) dist_ij[i][j] * X[i][j][k] <= Mdist; 


// (8) That the quantity of items delivered to consumers by all vehicles is equal to the demand off products required for every order placed by a client 

  forall(i in P)  

  sum(k in K) D[i][k][1] == demand_il[i][1]; 

// (9) Each vehicle's maximum capacity is not exceeded by the product weight of the orders on it.

 forall(k in K)  

 sum(i in P) D[i][k][1] * item_l_W[1] <= veh_k_Cap[k];
 

// (10) The total weight of all orders in a vehicle's route must not exceed the vehicle's capacity forall(k in K) sum(i in P, j in P: i!=j) demand_il[i][1] * X[i][j][k] * item_l_W[1] <= veh_k_Cap[k];

 // (11) Each vehicle leaves the construction material store the total weight of all goods from all orders must not exceed the vehicle's loading capacity. 

 forall(j in J, k in K, i in I: j>1) 

 item_l_W[1] *  S[i][j][k][1] <= veh_k_Cap[k]; 

// (12) The total weight of the products on each vehicle to ensure that it does not exceed the vehicle's load capacity 

forall(i in P, j in P, k in K: i!=j)

item_l_W[1] *  S[i][j][k][1] <= X[i][j][k] * veh_k_Cap[k]; 

// (13) All vehicles must be empty while returning to the building material store 

 forall(k in K) 

 sum(i in P, j in I) item_l_W[1] * S[i][j][k][1] <= 0; 

// (14) Depots cannot exchange goods with each other 

  forall(i in I, j in I, k in K) 

    X[i][j][k] == 0; 

// (15) Each center has at least one vehicle. 

 forall(k in K) 
  (sum(i in P, j in P: i!=j) X[i][j][k] >= 1) => (sum(i in I, j in P: i!=j) X[i][j][k] == 1); 

}
execute {
  var totalCost = 0;
  for(var i in P)
    for(var j in P)
      if(i != j)
        for(var k in K)
          totalCost += veh_k_FC[k] * X[i][j][k] + dist_ij[i][j] * veh_k_VC[k] * X[i][j][k];

  for(var i in J)
    for(var j in J)
      if(i != j)
        for(var k in K)
          totalCost += veh_k_DC[k] * X[i][j][k];
}