Task dependency can be edited at any point in time. Dependency type and lag time of already existing dependencies can be edited, and the entire dependency can be disabled/deleted to reflect the planned construction sequence.
The list of dependencies on the task are shown under the Dependency List option given on a task. The type of dependency and the dependency lag can be changed with this option.
The following steps will guide you to edit task dependencies:
Double click on the task bar in the Gantt chart
Click on Dependency List
To edit a particular dependency, click on the Edit (pencil icon) shown besides the predecessor or successor task displayed
After the required changes are done, click on Save to update the dependency
Enable / Disable Dependencies:
By default all dependencies are enabled. The button to the left of the dependency is always on. To disable a dependency, disable the button provided.
The steps to edit activity dependency is similar to edit task dependency, please read 3.14 Edit Activity Dependency to know more.