Working with hammocks
Hammocks are similar to expanded tasks and summary tasks except that:
- Hammocks summarise individual tasks, whereas expanded tasks and summary tasks summarise whole bars.
- When you summarise tasks using a hammock, the tasks are not moved from their original position in the chart.
Hammocks are purely summaries: they do not own or contain subordinate tasks, unlike expanded tasks and summary tasks.
You can use hammocks to store summary information for tasks which might be unrelated in the chart or project. Hammocks are sometimes known as roll-ups because the values on the tasks within the hammock are rolled up into total values which are stored on the hammock.
If you want to create a hammock between the finish of one task and the start of another task, create a milestone at the finish of the first task and at the start of the second task, then hammock the milestones.
You can specify whether to display hammocks using their standard appearance, as normal tasks, or as subheadings.
You can move hammocks vertically, but not horizontally.

- On the Home tab, in the Insert group, click Hammock. A hammock is created at the bottom of the bar chart. If a bar or task is selected when you use the Hammock command, a hammock is created on a new bar above the selected bar or task. If you have specified that hammocks should be displayed in the project view, the hammock appears in the project view, within the project hierarchy.
- Type a bar name in the spreadsheet to identify the new hammock.
Hammocks are always created on a new bar line. You cannot create or position a hammock on the same bar as other tasks, except other hammocks.
If you have specified that hammocks should be displayed as subheadings, any hammocks that you create will only be visible as tasks in the bar chart until you refresh the current view, at which point they will disappear.
To add tasks to a hammock, do any of the following:
- Drag a task and drop it on the hammock in the bar chart.
- Drag a task and drop it onto the hammock in the project view.
- Right-click a task then select Add to Hammock. The Select Hammock dialog appears. This dialog lists the hammocks available in the project. Select the hammock to which you want to add the task, then click OK.
A copy of the task is displayed below the hammock but the original task is not moved.
You can add tasks from anywhere within the project to the same hammock. A hammock can contain further hammocks, expanded tasks and summary tasks in addition to normal tasks.
Hammocks are displayed as inverted summary tasks. You can expand and contract a hammock by double-clicking it. When a hammock is contracted, + symbols appear at both ends of the hammock to indicate that the task contains further bars:
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Contracted hammock |
Expanded hammock |
To remove a task from a hammock, right-click the task within the hammock then select Remove from Hammock. That task is no longer included in the hammock, but the original task is unchanged.
You can also add tasks to and remove tasks from a hammock by selecting the hammock then clicking in the Hierarchy group on the Home tab. The Edit Hammock Members dialog appears. The tasks that are currently included in the hammock are checked in the project tree on the dialog.
To add tasks to the hammock, select their check boxes on this dialog. To remove tasks from the hammock, clear their check boxes.
You can convert a normal task into a hammock by right-clicking the task, selecting the Make Into submenu, then selecting Hammock. The task is converted into a hammock to which you can add tasks using the techniques described above.
When a hammock is empty but has a duration greater than 0, you can convert it into a normal task by right-clicking the hammock, selecting the Make Into command, then selecting the Task command.
You cannot convert tasks that have one or more task activities into hammocks.

Either:
- Select the hammock that you want to delete in the bar chart and press DEL.
- Right-click the hammock that you want to delete in the project view and select Delete.
Deleting a hammock does not delete the tasks that the hammock summarises. If you delete individual tasks from within a hammock, the tasks are deleted both from the hammock and from the chart or summary group in which they are actually located. You can only delete a task from a hammock if you have access rights to delete the task from its chart or summary group. You cannot delete a task from a hammock if the task is located in a chart or summary group that is currently booked out.

If you have specified that hammocks should be displayed in the project view, you can display the contents of a hammock in a separate tab. You may want to do this in order to print the contents of a hammock on its own.
To display the contents of a hammock in a separate tab, right-click the hammock in the project view and select Open in New Tab.
Specifying how to display expanded tasks, summary tasks and hammocks
Moving expanded tasks, summary tasks and hammocks
Breaking down tasks into smaller steps using task activities