Decision Optimization

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arrivel time to the node by the arcs

  • 1.  arrivel time to the node by the arcs

    Posted Thu March 20, 2014 09:02 AM

    Originally posted by: Preemptive


     

    Hi, 

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

    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 : 

     

    c17: forall (v in V, i in I, j in ICF1 :j!=i, t in T: t > 0) 
    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==0)
    F[i][v][t] == 0; 
    the ordre of visit for vehicul is : 02516320 (  (..) lenth of the arc ) 
    0.....(10)........2.......(45) ......5.....(20).......1...... ..(28).......6........(61).... ....3.........(30)........... 2..........(10).......0

    normally : F020= 0  ; F221= 10  ; F522=55   ; F123=75   ; F624=103   ; F326=164   ; F226=194   ; 

     

    but here he put that fiv equal to the lenth of the arc like : 

    F020= 0  ; F221= 10  ; F522=45   ; F123=20   ; F624=28   ; F326=61   ; F226=30   ; 

     

    how can i resolve it??

    Best regards 

     


    #DecisionOptimization
    #OPLusingCPLEXOptimizer


  • 2.  Re: arrivel time to the node by the arcs

    Posted Sun March 23, 2014 05:49 AM

    Hi,

    are you sure your model is feasible and the solution you get is not a relaxed solution ?

    2 suggestions:

    Do not hesitate to use assert in your model to be sure about some facts.

    Do not hesitate to use logical constraints : == => and so on

    regards


    #DecisionOptimization
    #OPLusingCPLEXOptimizer