Decision Optimization

Decision Optimization

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  • 1.  problem with the arrivel time constraint

    Posted 03/31/14 01:38 PM

    Originally posted by: Preemptive


     

    Hi, 

    F[i][v][t] denotes the arrival time  at node i by vehicle v after traversing t-th arc.

     

    range T = 1..T_max; 
    c2 : forall (t in T,v in V)  
    sum ( i in I,j in J:j!=i)Xijv[i][j][v][t] <= U[v];  when Uv denote if vehicul v is used or not, 

    So, if x[i][j][v][t]==1 than F[j][v][t] must be equal to F[i][v][t-1] + t[i][j] since vehicle v arrives at node i after traversing (t-1) arc.

    so i have this constraint  to calculate the arrivel time for each node 

     

    c17: forall (v in V, i in I, j in ICF1 :j!=i, t in T) 
    F[i][v][t-1] + item (TIJ,<i.i,j.j>).temp - F[j][v][t] <= M *( 1 - Xijv[i][j][v][t]); 

     

    c23 : forall ( v in V,i in ID, t in T: t==1) : (departure time from the node ID : depôt node 0) 
    F[i][v][t] == 0; 

     

    the ordre of visit for vehicul is : 0250 (  (..) lenth of the arc ) 
    0.....(10)........2.......(45) ......5.....(20).......0

     

    normally i should have this result : F021= 0  ; F221= 10  ; F522=55   ; F023=0 ; 

     

    i have errors : opl can not exrtract expression {1}

     

     

     


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  • 2.  Re: problem with the arrivel time constraint

    Posted 04/01/14 02:54 PM

    Hi,

    can you post your model and data ?

    regards


    #DecisionOptimization
    #OPLusingCPLEXOptimizer


  • 3.  Re: problem with the arrivel time constraint

    Posted 04/01/14 04:49 PM

    Originally posted by: Preemptive


    Hi ALEX, 

    in the attachment my model.

    Best Regards


    #DecisionOptimization
    #OPLusingCPLEXOptimizer


  • 4.  Re: problem with the arrivel time constraint

    Posted 04/03/14 05:16 AM

    Hi,

    in ct17 can you try to replace

    c17: forall (v in V, i in I, j in ICF1 :j!=i, t in T) by

    c17: forall (v in V, i in I, j in ICF1 :j!=i, t in T: t!=1)

    ?

    regards


    #DecisionOptimization
    #OPLusingCPLEXOptimizer


  • 5.  Re: problem with the arrivel time constraint

    Posted 04/03/14 05:57 PM

    Originally posted by: Preemptive


    no there is the same problem. 

    but i added an athor constraint (17a) and it worked fine, so 

     

    c17: forall (v in V, i in I, j in ICF1 :j!=i, t in T:t>1) 
    ( Xijv[i][j][v][t]== 1 ) => (F[i][v][t-1] + item (TIJ,<i.i,j.j>).temp == F[j][v][t]); 
     
    c17777: forall (v in V, i in ID, j in ICF1, t in T:t==1) 
    ( Xijv[i][j][v][t]== 1 ) => (F[i][v][t] + item (TIJ,<i.i,j.j>).temp == F[j][v][t]);
     
    c23 : forall ( v in V,i in ID, t in T: t==1)
    F[i][v][t] == 0; 

    i think now that i have a problem with the constraint 19 constraint insure that suplier must be visited before his customer so node 3 must be visited before node 5 like 

     


    0.....(32)........3.......(64) ......5.....(20).......1...... ..(28).......6........(63).... ....2.........( 10 ) ......0

     

    Best regards 

     



     

     


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    #OPLusingCPLEXOptimizer


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