Efficient project planning with the adequate work package size

According to the PMBOK® Guide (sixth edition of the Project Management Institute Global Standard) the term work package means the work that is defined at the lowest level of the work breakdown structure; thereby costs and duration are estimated and controlled, too.

Thus, work packages are the basic components of a project. A lack of clear definition of work packages leads to a project on “shaky ground” in consequence.

But let us take a closer look at individual work packages. Why are they that important?

To make the “big picture” and thus the project manageable, it is necessary to break it down into smaller working units. This turns the individual units into steps that you can plan and control. They are called work packages.

The “mother of all plans”, the work breakdown structure, is developed through the chronological or functional structure of the individual work packages. To maintain clarity, the project manager should pay attention to a standardized structure. Work packages are the basic here.

The “big picture” is divided into small and straightforward pieces that are structured functionally or chronologically. This structure shows the unity within the entire project. This shows that if even one piece (work package) of the puzzle  is missing, the puzzle (project) will not be complete.

Optimal size of work packages

Size according to project scope:

In many project management texts, you can read that work packages should not contain more than five to a maximum of twenty man-days. This may be a benchmark in many areas, but it does not say anything about decisive criteria (such as the amount of cost or workload).

Choosing work packages that are too small will quickly make a project unclear. Work packages that are too large can lead to poor control.

However, in most cases the following rule of thumb helps:

A work package should cover approx. 5% of the project scope!

If we start from these percentage calculations, the length of the work packages can be better calculated. Despite everything, a value of approx. twenty work packages (resp. a value of about 5%) is a good value for a project.

Size according to the reporting period rule:

With this rule, the length (duration) of the work packages is determined by the reporting period. If, for example, the project is reported on a weekly basis, the work packages should not take longer than one week.

This method makes the measurement of the progress easy to display. With this method, a work package can have the status “not started” (0%), “in progress” (50%) or “finished” (100%). If a work package appears with 50% in the first reporting week and with 50% in the second week again, something seems to be delayed here.


It is obvious to see that a default of how long a work package should or may be, is not a really good idea for a project. In fact, the length of work packages should be based on the project duration and the complexity of a project as well as its tasks.

With a correct “tailoring” of the work packages, an overload can be prevented during project control, since in these cases the individual work processes within the work packages are not tracked, but only the completion. And this is the job of the person responsible for the work package.

Also, sufficient big work packages provide motivation for the staff, as they are given scope of action, they are responsible for by themselves.

KLUSA offers this function with its work packages structure. Also, a person can be assigned responsible for each work package. The progress of the work packages can be calculated using either a manual or an automatic mode. The progress resp. success status is displayed directly as a progress bar within the Gantt chart. This makes the work of the project manager easier, too.

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