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Chapter 11 - Work Package

Part 2


The lowest hierarchical classifications in each branch of a WBS are known as work packages (WP). They cannot be sub-divided any further. On the other hand, tasks that are sub-divided are called sub-tasks (ST). WPs can be found at any hierarchical level and responsible persons can be project team members, departments of the company or even external companies. Persons responsible for the respective work package (work package owner) report to project management on progress and don't need necessarily to know the holistic context of the project.

A work breakdown strucutre subdivides tasks into sub-tasks and work packages. Numerical coding of the WPs is a great idea.

Work package descriptions

Routine work packages must always be included in the WBS, since they also have to be performed and will consume resources. If work packages are non-routine, it is necessary to provide a detailed description of them according to a specific scheme. There are no firm rules, however, for formulating such descriptions. Each organisation can define them in accordance with its own requirements. As a minimum, however, the descriptions should always include:

  • Name, number, version and status (planned, tested, released) of the work package
  • Brief description of content
  • Projected results to be obtained
  • Prerequisites for performance (e.g. deliveries required)
  • Projected commencement and completion dates or projected duration
  • Projected costs (generally unit costs, e.g. person days)
  • Person responsible for the work package

Often, further information is given, such as

  • regulations that staff must observe when performing the work packages (e.g. safety regulations or the organisation's quality management manual), or
  • specific activities which need to be performed by the person responsible for the work package so that the work package can be executed.

The organisational unit with responsibility for the work package is in charge for preparing a detailed description of the activities that must be performed, in order to realise it. If a work package is further divided, in general the project management office (PMO) has not to be informed. By the time that the work package is specified, the person in charge provides the work package description to the PMO. After all, the project manager is responsible for the timely implementation of the project within budget and in compliance with the agreed quality standards and has to make sure everything is on track.

Rules for work package creation

The following general guidelines can be formulated for the creation of WPs:

  1. Only one person should be accorded responsibility for each work package - irrespective of how many people will be working on it.
  2. In phase-oriented project management, it should be possible to assign each work package to one specific phase. Exceptions are multi-phase tasks, such as the ongoing monitoring of costs.
  3. Tasks that are outsourced should be labelled as stand-alone sub-tasks or work packages.
  4. A clear specification should be formulated for each element of the WBS so that third parties can easily monitor, whether the work package or sub-task has already been carried out (otherwise the project manager will not be able to track the project's progress).

A work package should be, if possible, defined as a closed-end performance element that differentiates from another and is linked to other work packages in a clear and straightforward way.

The time allocated for completing the work package should be appropriately short in comparison to the overall project lifecycle. Otherwise, there is a risk that the project manager identifies a delay too late to implement effective counter measures. Work packages that are performed throughout the entire project, such as "planning and monitoring time schedules" are exceptions.

Defining the appropriate size for work packages

Based on experience, the accuracy with which costs can be allocated to sub-tasks and work packages tends to decline exponentially beyond a threshold, as the number of planning and control units increases. On the other hand, too little detail (i.e. reviews too far apart), reduces the informativeness of the variance analyses carried out and makes cost management more difficult. The level of precision that is practical depends (to a great extent) on the system of data acquisition used.


Every organisation can make its own decision on the system of numbering to be used for sub-tasks and work packages in the WBS. Often, the numbers that are allocated indicate the level of the WBS to which the element belongs (identification key). One common way to code the WBS is numerically (= numbers, e.g. 1.0.0).

A classification key also exists. This indicates the organisational unit responsible for the element or the project phase where it occurs.

Since the sub-tasks and work packages generate costs during the course of the project, the coding also needs to satisfy the requirements of the organisation's accounting department.

Common mistakes and omissions

Many project managers are reluctant to spend the time on creating a WBS. They prefer to go straight to time scheduling. This is dangerous - especially since some sub-tasks and work packages use up resources even though they are not included in the time schedule. Examples of this are the various project management tasks that have to be done again and again, such as deadline and cost monitoring.

Problems also occur if the team actually creates a WBS in their initial planning euphoria, but then fails to integrate necessary changes during the course of the project.

Sometimes, the planners forget important sub-tasks, such as systematic project hand-over. Often, they will make the excuse that they know it anyway, but later on, no one remembers to do the concerned tasks (of course).

How the story ends…

Just to make sure, Dr. Rogers suggests that the team should meet up again in two days to review the work breakdown structure. Everyone agrees. The work packages are assigned to people so that all members of the team have time to think about them and prepare for the second workshop. "One last thing", Dr. Rogers says, "When you assign the tasks and work packages to the responsible persons, please make sure, that all information about the progress is communicated clearly, no person in line should be skipped."