# PRJ: How to Build a Hammock Task

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## SUMMARY

A "hammock" task is dependent on external dates for both its start and finish dates and, ultimately, its duration. The name, hammock task, is derived from the way a hammock's shape is determined by the distance between the points to which it is attached.

As scheduled dates in other tasks change, the duration and start and/or finish dates of the hammock task change as well. In other words, given three tasks A, B, and C, task B must start on some date from task A (date A) and task B must finish on some date from task C (date C). For an illustration of this task B, see Example 1.

```        A
|           C
|-----B-----|
```
The span of time between dates A and C dictate the available time to accomplish task B. As Date A changes, the start date for task B changes as well; If date C moves, task B must finish appropriately. The difference between dates A and C is the duration for task B. See example 2.

### Example 2--Date A Late, Date C Early

```           A
|     C
|--B--|
```

To build a hammock task between two other tasks in Microsoft Project 2007 and earlier versions, follow these steps:
1. Create or determine three tasks that correspond to A, B, and C in the example above.
2. Highlight the cell that contains date A (the date that will determine when task B starts).
3. On the Edit menu, click Copy (Cell).
4. Highlight the cell that contains the Start date for task B (the hammock task).
5. On the Edit menu, click Paste Special, and click Paste Link.
6. Highlight the cell that contains Date C (the date that will determine when task B finishes).
7. On the Edit menu, click Copy (Cell).
8. Click the cell that contains the Finish date for task B (the hammock task).
9. Click Edit, click Paste Special, and click Paste Link.

1. Create or determine three tasks that correspond to A, B, and C in the example above.
2. Highlight the cell that containes date A (the date that will determine when task B starts).
3. On the Task tab, click copy.
4. Highlight the cell that contains the Start date for task B (the hammock task).
5. On the Task tab, select the Paste drop-down, and then click Paste Special. Select Paste Link and then click OK.
6. Highlight the cell that contains Date C (the date that will dtermine when task B finishes).
7. On the Task tab, click Copy.
8. Click the cell that contains the finish date for task B (the hammock task).
9. On the Task tab, select the Paste drop-down, and then click Paste Special. Select Paste Link and then click OK.

NOTE: The Date format on the Options dialog box muc be set to show time as well as date, such as Wed. 1/28/09 12:33 PM, otherwise the linked task will use the beginning of the day specified instead of the beginning of the next day.

### Notes and Cautions

• Do not specify a predecessor for a hammock task. Only Paste Linked dates will determine start and finish. You may specify predecessors for the tasks from which dates are paste linked into the hammock task.
• A negative duration (finish date is before start) is not allowed. Depending on the source of the dates, the hammock task may turn into a milestone (zero duration) or erroneously calculate duration before the finish date or after the start date.
• An OLE update is different from a calculation. You may not see expected changes in the hammock task after calculating project. From the Edit menu, click Links to edit/update OLE links (Paste Links). Alternatively, press the F9 function key twice.
• Because the hammock task relies on other tasks for start/finish information, anything that affects those other tasks (resource leveling, constraints) will ultimately affect the hammock tasks dates.
• If the hammock task is a child to a summary task, it may inherit predecessor behavior from the summary task that may affect its duration and/or start and finish dates or create a circular relationship.

## Properties

Article ID: 141733 - Last Review: September 19, 2011 - Revision: 5.0
##### APPLIES TO
• Microsoft Project 2000 Standard Edition
• Microsoft Project 98 Standard Edition
• Microsoft Project 4.1 Standard Edition
• Microsoft Project 3.0 Standard Edition
• Microsoft Project 4.0 for Macintosh
• Microsoft Office Project Professional 2007
• Microsoft Office Project Professional 2003
• Microsoft Office Project Standard 2007
• Microsoft Office Project Standard 2003
• Microsoft Project 2002 Standard Edition
• Microsoft Project 2002 Professional Edition
• Microsoft Project Professional 2010
• Microsoft Project Server 2010
• Microsoft Project Standard 2010
##### Keywords:
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