SETS:
   TASKS / 
    @OLE( 'C:\LINGO5\SAMPLES\PERTOLE.XLS', 'TASKS')/:
     TIME, ES, LS, SLACK;

   PRED( TASKS, TASKS) / 
    @OLE( 'C:\LINGO5\SAMPLES\PERTOLE.XLS', 
     'BEFORE', 'AFTER')/:Z;
ENDSETS

DATA: 
   TIME = 
    @OLE( 'C:\LINGO5\SAMPLES\PERTOLE.XLS');	
    @OLE( 'C:\LINGO5\SAMPLES\PERTOLE.XLS') = ES, LS;	
ENDDATA

@FOR( TASKS( J)| J #GT# 1:
 ES( J) = @MAX( PRED( I, J): ES( I) + TIME( I))
);

@FOR( TASKS( I)| I #LT# LTASK:
 LS( I) = @MIN( PRED( I, J): LS( J) - TIME( I));
);

@FOR( TASKS( I): SLACK( I) = LS( I) - ES( I));

ES( 1) = 0;
LTASK = @SIZE( TASKS);
LS( LTASK) = ES( LTASK);