The hierarchical relationships between the project lines are defined by the project structure. All project lines have a relationship with the line that is above them in the hierarchy. Such a parent line is always of the type 'Project', 'Subproject' or 'Phase'. Other types of lines cannot have any underlying lines.

A line with underlying lines will have a start date, a finish date and a lead time based on the underlying lines, as in the subproject 'Hydraulics' below:

Finish-to-start relationships are very common between project components. They indicate that a particular component can start as soon as another component has been completed:

You can specify an overlap if the second activity can start before the first has completed in full:

A start-to-start relationship indicates that two project lines will start at the same time:

Finish-to-finish relationships indicate that two project lines will end at the same time: