Widget Co

    {  Exmpl8.4-6_WidgetCo.mpl  }

    {  Winston, Operations Research, Applications and Algorithms, 4th ed.  }

    {  Chapter 8.4,  Example 6, CPM/PERT,  Size: 9x8,  Page 433 }


TITLE
    WidgetCo;

INDEX
    task  := (ST,A,B,C,D,E,F,FIN);
    task2 := task;

DATA
    Duration[task] := (0,6,9,8,7,10,12,0);
    Predecessor[task,task2] := [C,A,1,
                                C,B,1,
                                D,A,1,
                                D,B,1,
                                E,D,1,
                                F,C,1,
                                F,E,1,
                                FIN,F,1];

VARIABLE
    StartProcess[task];
    Complete;

MODEL

    MIN TotalTime = Complete;

SUBJECT TO

    Order[task,task2] WHERE (Predecessor > 0):
         StartProcess >= StartProcess[task:=task2] + Duration[task:=task2];

    Finish[task=FIN]:
         StartProcess = Complete;

END