Making an event start when another event ends
Preceden allows you to specify that one events starts when another event finishes.
We call these events dependents because they depend on another event to determine its dates.
How to specify a dependency
Let's pretend that you're a software developer and are using Preceden to plan the release of a new project.
In one of the layers you want to have two events: Alpha and Beta representing where you and your team are at in the development process.
For the Alpha phase, you add an event to your timeline called Alpha with a start date of January 2016 and an end date of May 2016:
For the Beta phase, let's say you estimate it will take 6 months. You have a few options for adding it to your timeline:
- Fixed start and fixed end date - Add an event with a start date of June 2016 and an end date of November 2016.
- Fixed start date with a duration - Add an event with a start date of June 2016 and an end date of 6 months.
- Dependent start date with a fixed end date - Make Beta a dependent of Alpha and set the end date to November 2016.
- Dependent start date with a duration - Make Beta a dependent of Alpha with an end date of 6 months.
My preference is the last option because you don't have to specify the actual start date of the event (and it will automatically change if you ever change date for Alpha, the event it is dependent on) and if you specify the duration then the end date will automatically be calculated whenever the start date changes.
Here's how to do it:
When you go to add the Beta event, you can click the link below the start date field.
Note that you'll only see this option if you have multiple events on your timeline and you've enabled dependencies via Settings > Dependencies.
You can then select from a list of existing events on your timeline to specify which one this event is dependent on. You can also set the end date to 6 months to make the event's end date come 6 months after its start date:
After you add Beta to your timeline, you'll see that it starts when Alpha ends and that it lasts 6 months:
Deleting an event that has dependents
In the example above, Beta depends on Alpha. What happens if you delete Alpha?
If you delete an event that has dependents, Preceden will update the dependents to reflect the deleted-event's end date.
In this example if we delete Alpha, then the start date for Beta would be set to Alpha's actual end date, June 1, 2016.