Task dependencies in project management describe how tasks are related to one another and in which order they should be completed. Properly managing these dependencies is key to keeping a project on track and ensuring its successful completion.
In this article, we’ll look at the key aspects of working with dependencies in GanttPRO.
Types of dependencies
In GanttPRO, you can create dependencies between tasks straight from the Gantt chart, and also in Task settings or using the Predecessor field in Standard fields.
On a Gantt chart, dependencies are depicted with orange arrows.
Once you add a new task, hover over its bar on a Gantt chart. You will see little circles at each end of it. To set task dependencies, just connect those circles according to the type of the dependency you need.
There are 4 different types of dependencies:
1 Finish to Start (FS) means that task B (successor) can’t start before task A (predecessor) finishes.
Example: in a software development project, developers start coding a feature only after the feature requirements have been elaborated and approved.
2 Finish to Finish (FF) means that task B can’t be finished before task A finishes.
Example: in a construction project, the construction part finishes once both the interior and exterior are fully completed.
3 Start to Start (SS) means that task B (successor) can only start after task A (predecessor) has started.
Example: in a product development project, prototype development can start once the concept ideation task starts.
4 Start to Finish (SF) means that task B can only be finished once task A has started.
Example: in a project involving migration to another IT system, the old system that has been used can be only deactivated once the new solution has been put into action.
Note that if you increase or decrease the amount of time for a task with dependencies, all the other tasks it is connected to, will also move on a timeline. In that case, you will also see the indication of the completion delay for all the connected tasks.
Deleting dependencies
To delete dependencies between tasks on your Gantt сhart, click on the arrow between the corresponding tasks 1 and select Delete dependency 2 in the window that will appear.
Alternatively, open Task settings and remove dependencies from there by clicking on the delete icon when you hover over it.
Adding lags and leads
Sometimes you may have situations when one of the tasks or subtasks in a chain is to start with a delay (lag time) after the preceding task is finished. Or vice versa, the following task needs to start when the preceding one is still in process (lead time).
In GanttPRO, you can easily keep gaps between tasks or create overlaps between them even when the Auto Scheduling is enabled. So if you need to move the group of tasks on the timeline, the dependencies will be kept just the same as you have set them up.
If you need to set up lead or lag time, click on the dependency between the tasks and you will see the settings “Setup required lag/lead of task”. All you have to do now is to add or decrease the required values:
- You can set up the lead time with the help of a negative value (-).
- You can set up the lag time by adding values (+) to create a gap between the tasks.
Note that the values of the gap (hours, days, weeks, months) are set based on the Duration step set up for your project.
This is how a 2-day delay between two tasks will look like on a Gantt chart.