In Structure.Gantt, duration for each task can be calculated in one of three ways.
Automatically
When tasks are automatically scheduled or manually scheduled without a fixed duration, their duration is calculated automatically, based on their work estimates and the Work Estimates settings associated with that task.
To adjust the duration of these tasks:
- Edit the task's work estimate fields, or
- Drag the left or right side of the task bar.
Dragging Automatically Scheduled Tasks
If you drag the right side of a task that is automatically scheduled, the task remains in automatic scheduling mode, but its duration is updated. If you drag the left side of the task, the task becomes manually scheduled based on the new Start Date and it's duration is updated accordingly.
In either case, the duration will be updated as follows:
- If you are using Jira Time Tracking, the Original Estimate field value will be updated (for issues with no time logged) or the Remaining Estimate field value will be updated (for the issue with time logged)
- If you selected Prefer Custom Estimate over Time Tracking for Work Estimates, the value in the custom estimate field will be adjusted based on the ratio defined in the configuration.
Dragging Manually Scheduled Tasks
When you drag the side of a manually scheduled task, if the side of the task you are dragging was manually scheduled, the corresponding field (Start or Finish Date) will be updated to the new date and the duration will be updated accordingly. Otherwise, only the duration will be updated.
In either case, the duration will be updated as follows:
- If you are using Jira Time Tracking, the Original Estimate field value will be updated (for issues with no time logged) or the Remaining Estimate field value will be updated (for issues with time logged)
- If you selected Prefer Custom Estimate over Time Tracking for Work Estimates, the value in the custom estimate field will be adjusted based on the ratio defined in the configuration.
Based on Start and Finish Dates
When tasks are manually scheduled and have both a manual Start and Finish Date, the task has a fixed duration, spanning the time between its Start Date and Finish Date.
To adjust the duration of a fixed duration task, drag either side of the task bar. This will update the task's Start or Finish Date, and the duration will be adjusted accordingly.
Based on Sprints
When tasks are scheduled based on sprints, they have a fixed duration corresponding to the length of the sprint. It is not possible to adjust the duration of these tasks, except by removing them from sprint-based scheduling or changing your sprint duration settings.