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Insights into how hammocks are used in Project Planning to make your life easier than a sea breeze!
Author: Ben Ames Head of Business Development at i3Works
Hammocks may conjure up images of palm trees, azure oceans and mojitos, but their appeal doesn’t just end there, they are also used in Project Planning to make your life easier than a sea breeze. In my view a hammock should be high up, be able to stretch over any length, and should only be sat in by Project Managers (okay, I’m joking about the last bit).
‘Hammock’ activities (also known as the ‘level of effort’ activity type in Primavera) are those that ‘hang’ between start and end points (Activities or Milestones) within a schedule. These are useful for ‘non-deliverable focussed’ activity that last for the duration of a work package, phase, project or programme – no matter how that duration expands or contracts. A Project’s management and support effort is normally captured in this way i.e. Project Planning or Risk Management. I geekily refer to these sort of activities as being PAU (Project As Usual).
In my view, hammock activities should not read ‘Project Planner’ or ‘Risk Manager’ as they should be about the type of work being required (Project Planning or Risk Management) not the person required. For instance the Project Manager may be spending a lot of time doing risk management and that effort should be reflected within the Risk Management hammock. Likewise if a Project Manager is working on a ‘deliverable focussed’ activity (e.g. signing off a technical drawing) rather than something that is PAU, they should be assigned to this activity as well as their usual ‘Project Management’ hammock.
The use of hammocks should add clarity to your project resourcing, however they should not be ‘over-used’ and are not a substitute for sufficiently resourcing the detailed deliverable activities that should make up the vast majority of the project plan. As with the whole of the Project (of which the plan is just a reflection), the ‘doing’ should vastly outweigh the ‘managing’.
It is therefore useful to separate hammocks out and apart from the ‘deliverable’ activities so that the two activity types don’t get confused. Placing them in to their own WBS at the top (of the Work Package, Project etc) is a common way to do this. By all means steal my PAU acronym for this WBS name but you will often see these referred to as something generic such as ‘Management & Support’.
Promoting the use of hammocks can help to move people away from the ‘Project Plan as a Calendar’ mind-set – where recurring meetings are put in to the schedule to show effort being spent (a blog for another day) – as now they have another place to collect the recurring/ongoing effort of managing and supporting a project.
As hammocks hang between start and end points they are (by nature) zero float activities for the Work Package, Project etc to which they are associated. However, they are not the critical path. In Primavera the Level of Effort (LoE) activities will not show as Critical but in other software (such as EPM/MSP) they can. To solve this, just identify the hammocks within your schedule somehow (for instance by marking them in a text field) and filter them out when looking at critical path activities. If this is not applicable (for instance if other people have sight of your project and you don’t want to have to provide them with instructions regarding filtering) you can also stop them appearing on the critical path by reducing their duration by a unit of time (note that this doesn’t work in the MSP/EPM hint given below). For instance, if I want to show a Hammock activity for a work package lasting for 200 working days, I will add the activity with the Start Milestone as its predecessor, the End Milestone as its successor and the duration as 199 working days.
Hints:
- Hammock activities would, in most situations, be set as ‘Fixed Duration’ activities.
- In MSP/EPM you can set up hammocks to take their duration automatically without the need to constantly re-adjust as changes happen. To do this, first identify the activities or milestones that mark the Start (predecessor) and End (successor) of the WorkpackageProject etc. For the Hammock’s predecessor, copy the finish date cell in the usual CTRL+C fashion. Highlight the start date cell for the hammock activity, but select ‘Paste Special, Paste Link, Text Data ’. Likewise paste the successor’s Start Date in to the hammock’s Finish Date cell as ‘Paste Special, Paste Link, Text Data ’. Although this activity will now appear as though it has a constraint, the dates will change to reflect the duration between predecessor and successor (note that there can be a slight system delay).
