Creating interruptible tasks
To create an interruptible task:
- Create a task in the normal way, either by drawing it in the bar chart or typing into the spreadsheet.
- Either:
- Right-click the task, select Make Into from the menu that appears, then select Interruptible.
- Edit the properties of the task and select the Interruptible check box, in the Constraints group of fields, on the Task tab of the Bar and Task Properties dialog.
- Display the Interruptible field, found with the Constraint fields, in a spreadsheet column, then edit the field to specify that the task is an interruptible task.
The task becomes an interruptible task.
When you designate a task as an interruptible task, the task's current duration is copied into the Original buffer task duration field and any resource allocations on the task are converted into non-modelled allocations.
You can search for tasks that are ideal candidates for conversion into interruptible tasks - ie those tasks that have at least two incoming links, one of which constrains the start of the task and one of which constrains the finish of the task - by using the Filter Wizard to filter for potentially interruptible tasks.
You can turn an interruptible task back into a normal task by editing the Interruptible field or by right-clicking the task and selecting Make Into - Task. Note that you cannot turn expanded tasks, summary tasks, hammocks, milestones or buffer tasks into interruptible tasks. If you turn an interruptible task back into a normal task, the interruptible task setting is removed automatically from the task.
Interruptible tasks and ALAP placement
Configuring interruptible tasks to be positioned ALAP (As Late As Possible) does not make logical sense, as two conflicting constraints would be applied to the same task. For this reason:
- You cannot configure interruptible tasks to have ALAP placement.
- You cannot change ALAP tasks into interruptible tasks using the Bar and Task Properties dialog or spreadsheet.
- If you change an ALAP task into an interruptible task by right-clicking and selecting Make Into - Interruptible, the task is set automatically to be ASAP.