Change  predecessor relationships 
 - Choose Project, Activities.
- Select the activity whose predecessor relationship you want to change.
- Display Activity Details, then click the Predecessors or Relationships tab. 
 
 To add a predecessor, click Assign in the Predecessors tab or in the Predecessors area of the Relationships tab. Select the predecessor activity you want to add.
 
 To change a relationship type, double-click the appropriate Relationship Type field, then select a new relationship type.
 
 To change a lag time value, double-click the appropriate Lag field, then enter a new time value.
 
 To remove a predecessor, select the predecessor you want to remove, then click Remove.
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