How to create dependencies like version 2

Dependencies and Constraints

Version 2 contained a single type of dependency, and they were quite strict: Version 2 dependencies tied two events together with an exact offset between them.

In version 3, we have extended the options further by splitting functionality into Dependencies and Constraints:

  • Dependencies are simpler, and help enforce a fixed order of events without being strict about the time:
    • If Event B is blocked by Event A, that means Event B cannot start until after Event A has finished
    • However, it doesn't matter whether Event B starts immediately after Event A, or if there is a 6 month gap: both scenarios satisfy the dependency that has been created
  • Date constraints are more flexible and provide more options, but are therefore a little more complex:
    • Options allow constraints enforcing an exact time gap, or relative gaps

You can read a lot more detail about this in Dependencies and Constraints

Recreating version 2 style dependencies as Constraints

If you want to reproduce the type of dependencies that existed in version 2, you will need to use Date Constraints.

To create such a Constraint:

  1. Select the event that you want tied to another event (if the gap is not already correct, it is best to select the event you want to move when you create the constraint)
  2. In the Item Inspector, click on the Constraints tab, and then click on the + button underneath Date Constraints
  3. In the popup, select:
    1. Start
    2. Equals start of / Equals end of (depending on your preference)
    3. [Your chosen other event]
    4. Enter an offset, or leave blank for "0 seconds"

  4. Click Add to create the constraint:

How does Aeon Timeline 3 handle moving items with constraints

Again, Aeon Timeline 3 offers a bit more flexibility here.

In Aeon Timeline 2, once you created a constraint, you were unable to move or edit the date of any event in a chain other than the very first originating event.

With Aeon Timeline 3:

  • You can decide in settings whether linked events will be automatically moved when you drag an event, or if you want them to remain in place (in which case, the constraint will be marked as violated)
  • You are drag either event in a dependency (you are not restricted to dragging the first event in the chain)
    • When you do, all other connected events will move automatically (assuming you have this enabled in the setting above)
  • If you want to ensure an event is never moved, you can click the lock icon next to its date
    • Once an item is locked, its date will not be affected by dependencies or even user action until you unlock it