Home » BIM news » Functions and advantages of Work Breakdown Structure (WBS)

Functions and advantages of Work Breakdown Structure

Functions and advantages of Work Breakdown Structure (WBS)

How does it work and what are the real benefits of using Work Breakdown Structures in organizing and planning activities? (part 2)

In the previous focus we introduced the general characteristics of Work Breakdown Structures, analyzing the structure and its basic characteristics. In this study we’ll now be taking a look at how it works and where the main advantages are.

Milestone identification

Milestones are goals or intermediate objectives that are identified within the project with the aim of monitoring their progress in time.

Some examples could be:

  • the end of testing of an electrical system
  • signing a contract
  • the end of testing of a water system
  • etc.

The identification of given milestones can be represented by a Gantt chart.


Gantt chart milestones

The rules to follow for a correct WBS structure

When creating a WBS, whatever the type of project, you first need to know which objectives must be met at a preliminary stage.
Without proper planning, it would be complicated to define the individual activities to be carried out.

The level of decomposition of the various work phases must allow us to define the optimized “work packages” that must be clear and well defined, avoiding duplicates when assigning tasks.

Project decomposition should be in the logic of defining various sub-levels of disaggregation, such as:

  • in stages: the breakdown takes place on the basis of the various phases leading to the realization of an objective (eg: planning, procurement, construction, etc.)
  • for processes: the decomposition is based on the processes that lead to the realization of deliverables. It is generally used in high standardization works (eg. foundations, walls, roof, etc.)
  • by location: decomposition is carried out according to the place of construction (eg: building site London, building site Paris, etc.).

WBS and the 100% rule

One of the basic rules behind the creation of WBS is the 100% rule which states:

A WBS must include 100% of the work defined by the project and all the necessary – internal, external and contract aspects – to the realization of the project, including the management of the project itself.

The rule applies to all hierarchy levels: the sum of the “child” levels (lower node) must be equal to 100% of the work represented by their “father” (upper node).

The rule also applies to the level of activity: the work represented by the activities in each work package must be 100% of the work necessary to complete the entire package.

Let’s see how to apply this rule to our previous example.

The 100% rule in the Work Breakdown Structure

The 100% rule in the Work Breakdown Structure

The advantages of WBS

As seen before, using a WBS within a project involves a number of advantages, such as:

  • identify responsibilities for each phase of the project
  • describe activities to be carried out in a clear and complete manner, avoiding any ambiguities
  • assign a task to a specific person or resource avoiding duplication in the assignment of tasks
  • facilitate communication between the different professional roles involved in project execution
  • improve understanding of the project by all the subjects involved
  • improve understanding of the project by external subjects