Level of Effort (LOE) or hammock activities do not produce any one particular deliverable, but they span the entire duration of the project. Yes, it is possible to define hammock activities in Microsoft Project.
Deliverables in Microsoft Project are defined by summary tasks, and the work required to produce those deliverables by detail tasks. But how does one define project efforts that are not directly associated with the production of a deliverable, but span the entire duration of the project?
As mentioned above these efforts are defined by LOE or hammock tasks. Examples of hammock activities include project management and administrative efforts. Both these efforts expense labor resources, but neither one directly produces a deliverable, and they are unique in that they span the entire duration of the schedule. Hammock activities support schedule updates, as they automatically expand and contract as schedule task durations increase and/or decrease in length.
LOE and Hammock Activities
This article describes how to define a LOE or hammock activities in Microsoft Project 2013 to support project management, administrative, or similar efforts. Note that this article focuses on the planning stages of project scheduling. It does not address the execution or schedule update phase, which has proven to be a more delicate process when LOE activities are included in the Microsoft Project schedule.
A diagram of a LOE task is displayed in Figure 1.
The LOE task in this pictorial links to the start of the first activity and finish of the last activity. Because the LOE task spans between the first and last activities they are often called hammocks.
We have in Figure 2 our demonstration schedule.
Note the new task below Start Project. This new task will become our LOE task representing the project management effort. First set the duration type of this task to ‘Fixed Units’, Figure 3.
We are fixing the daily resource effort of project management, as it remains constant throughout the life of the project. We also use ‘Fixed Units’, because otherwise our hammock would not compute properly.
In Figure 4 we begin our hammock task definition by copying the start date from the ‘Start Project’ task.
We then paste special this date into the start date cell of the project management task, Figure 5.
In paste special toggle ‘paste link’ and select OK, Figure 6.
This creates a link between the start of ‘start project’ and start of ‘project management’.
We proceed by copying the finish date of project completion date task, Figure 7.
Paste special this finish date to the finish date of project management, Figure 8.
Again, toggle paste link and select OK, Figure 9.
The definition of our hammock is complete, and you may observe that it spans the entire schedule in Figure 10.
In Figure 11, we assign the foreman resource to the project management hammock task.
Note the cost of project management is $15,000. Now watch what happens when we increase the duration of ‘drain piping system’ task, Figure 12.
Our hammock project management task expands accordingly, and the cost of project management increases to $22,000. When we decrease ‘drain piping system’ to its original duration, the project management hammock contracts accordingly, and the cost decreases in proper proportion, Figure 13.
Task logic makes the scheduling effort significantly less tedious. Schedules that have proper logic automatically update task start and finish dates, in accordance with the schedule updates.
The LOE or hammock logic is unique because it spans the entire project duration, and automatically expands and contracts as activity durations in the schedule increase and decrease in length. The hammock logic is achieved in Microsoft Project 2013 by linking the start of the first task and finish of the last task to the hammock.
The hammock activities in Microsoft Project will automatically expand and contract as schedule updates increase and/or decrease project duration. Be aware that it may take Microsoft Project a moment or two to make the calculation and to display the adjusted hammock activities accordingly. Again, Microsoft Project hammock activities work well in the scheduling planning stage. Project execution and LOE activities is a whole intricate topic of investigation and discussion for another day.