How do you break down your project into tasks using the WBS structure?

Are you a project manager looking to structure your tasks to plan your project? Use the WBS (Work Breakdown Structure) method!

Breaking down the work to be done into deliverables and sub-tasks helps to organise your project into a clear, costable flowchart.

But how do you break down a project? And how do you make a good project WBS? You'll find a 4-step method, examples and tools in this article!

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WBS: definition and objectives

The WBS method is a project management technique that involves breaking down a parent project into child tasks, which are then divided into sub-tasks. The aim is to :

• structure the project
• identify its overall architecture
• visualise all the deliverables expected and the tasks to be carried out.

💡 The WBS, also known as the OTP (organisation chart of project tasks), or SDP (project breakdown structure), originated in the Project Management Institute's PMBOK guide.

The WBS can take several forms:

• a flowchart, the most common form of WBS,
• a mind map
• a list
• a plan.

7 advantages of the WBS

• Highly visual: at a glance, you can see all the work to be done, the priorities and the urgencies, and limit the risk of being caught off guard as the project progresses.
• In addition to the Gantt chart, it helps teams to better identify the dependencies between different tasks.
• It is an excellent communication tool for the various parties involved, and instils confidence in the customer.
• The project manager uses the WBS to allocate the total project budget to the underlying units.
• Improved risk management: at a glance, spot any malfunctions, i.e. incomplete branches or branches containing errors.
• Anticipate any delays in planning. Has a deliverable not been produced on time? It's easier to react to limit the impact on higher-level units in the same branch.
• A better distribution of efforts within the teams: the project roadmap is clearer, and it becomes easier to readjust according to the difficulties encountered during project management.

Example of a WBS

The following diagram gives you a visual example of a WBS. It shows :

• the project in its entirety, also known as the parent project ;
• broken down into deliverables, called child tasks;
• themselves divided into sub-deliverables, also known as sub-tasks, depending on the level of granularity required in relation to the complexity of each task...

... and so on, until the units at the base of the organisation chart are as manageable as possible for the teams: the tasks at the lowest level, called " work packages" or " work units", no longer need to be broken down.

How do you break down a project using the WBS method?

Step 1: Define the project to be delivered

Start at the top of the structure, with a macro vision of your project. Clearly define the contours of the total, finished project, the one you need to deliver to your customer.

This stage gives you the direction to follow and the meaning of each of the tasks that follow.

Example: a website creation project for a local business

Step 2: Identify the main deliverables

Next, identify the main deliverables directly below the finished project. Each deliverable marks out the progress of the project and contributes to its completion.

In our example, the main deliverables, or child tasks, are :

1. analysis of customer requirements
2. definition and validation of the project scope,
3. project planning,
4. site design,
5. site development,
6. the testing phase,
7. going live,
8. maintenance.

Step 3: divide the deliverables into sub-deliverables

Finally, divide each deliverable into sub-deliverables, or sub-tasks.

Our advice 👉 divide the sub-tasks into finer levels of granularity until the work packages at the final level are sufficiently costed and manageable, both in terms of budget and human resources.

Let's take our example again. The "site design" child task comprises multiple sub-tasks, such as :

1. defining the structure of the site based on what already exists and what new features need to be added,
2. creating mock-ups for each type of page,
3. thinking about the site's navigation
4. creating a graphic charter to ensure the visual consistency of the site, etc.

Step 4: Fill in the WBS dictionary

Nothing to do with that dear Robert! The WBS dictionary is a document that lists the content of each work package. Each work package has an entry that includes :

• the person in charge
• the deliverables
• the cost
• deadlines and deadlines,
• the main tasks to be carried out
• any other relevant information that helps to complete the work package.

This dictionary is useful for defining the project repository, with the WBS structure and the specifications.

How do you make a good WBS? Our advice on how to use it

Rule 1: follow the 100% rule

Applying the 100% rule means considering that a parent project forms a whole, containing all its "children".

This is because a set of sub-deliverables must always display all the work required for the higher-level deliverable.

Conversely, the sum of the units must not represent more than 100% of this higher level: the WBS method excludes any task that does not concern the project.

Illustration of the 100% rule:

Rule no. 2: avoid overlaps

When building your WBS, make sure that each unit is exclusive, and does not appear several times in different branches.

By avoiding overlaps, this rule protects you from any confusion over who is responsible for carrying out which tasks.

Rule no. 3: define the right fineness of breakdown

How do you determine it? For each work package, estimate :

• the time required to complete it
• the associated cost
• the resources needed to carry it out.

This rule helps you to be precise in your breakdown: if a deliverable can be quantified with a high degree of precision, it does not, a priori, require any further ramifications.

Rule no. 4: don't look for symmetry in the WBS structure

This principle follows on from the previous one: each branch of your WBS does not necessarily have to have the same number of levels, because the depth of the breakdown stops as soon as the lowest unit proves to be sufficiently quantifiable.

As a result, the final form of your WBS can be " asymmetrical".

Rule no. 5: aim for deliverables rather than actions

The best way to look at the project is in terms of results, not organisational or functional elements.

Our advice 👉 Define your various units in terms of deliverables rather than the actions required to achieve them. In this way, you gain flexibility in the process of carrying out each task.

Example of a WBS flowchart based on deliverables :

Choosing the right tool: Excel or dedicated software?

Sometimes all you need to build your WBS is a simple sheet of paper, a whiteboard or post-its. These tools are useful for brainstorming or exchanging ideas... but they quickly reach their limits.

👉 If your project is simple (few deliverables, few stakeholders), you can use Excel for your WBS. You can find examples of WBS structures to adapt and customise on the Internet.

👉 For medium- to large-scale projects, or when the teams are dispersed, using software is crucial for :

• build, and above all reinforce, the visual quality of the WBS - one of the most important prerequisites for its effectiveness,
• manage any changes to the diagram much more simply
• add a collaborative and agile dimension to your project.

🛠️ Which software should you choose to create a good WBS?

• The advantages of Lucidchart :
  • an easy-to-use, intuitive interface,
  • simple drag-and-drop operation
  • customisation of the flowchart created with your own deliverables,
• The advantages of monday.com :
  • a visual and intuitive tool,
  • a system of customisable tables to manage your tasks and sub-tasks,
  • visibility of the deadlines for each deliverable.
• The advantages of Gladys:
  • a customisable dashboard for tracking project weather, time spent per person, per task and per project,
  • a simple, highly polished and web-adaptive interface (which adapts to all types of screen),
  • a collaborative platform with tools tailored to your project management (Gantt, Kanban, Mindmap, etc.).

Common mistakes to avoid

Even with the best will in the world, a poorly designed WBS structure can cause havoc in your organisation. Here are the most common pitfalls to avoid.

1. Confusing tasks with deliverables
We can't stress this enough: the WBS is based on deliverables, not project tasks.
A work breakdown structure (WBS) details what needs to be done.
The WBS indicates what needs to be delivered.
It is a breakdown by result, not by action.

2. Creating unnecessary levels
A WBS structure that is too granular can slow down project management. Each level must have a real purpose. If you have to go as far as "level 12.3.2.bis", it's time to take your foot off the gas.

3. Forget the 100% rule
Each element of the WBS must represent 100% of the work to be done at its level. Not 80%, not 120%, but 100%. The rest is irrelevant.

4. Cutting and pasting without thinking
An example found online is tempting. But every project is unique. A prefabricated WBS can become a trap if it doesn't reflect your real objectives or resources.

5. Not involving the team
Team members need to be involved in breaking down the project. They often have a better view of the work to be done, particularly in certain phases.

6. Forgetting to update the WBS
A project moves. And your WBS structure has to keep up. If it remains static, it loses all interest in real-time monitoring.

7. Do without a suitable tool
Building a WBS on Excel is fine. But when the project gets bigger, a project management tool quickly becomes essential. It helps you to :

• visualise the levels
• allocate elements
• monitor progress.

After WBS

The WBS method provides an overview of the structure of a project at the start of the project, and of the course to be followed to complete it. Bear in mind that other complementary tools are available to make up for the shortcomings of the WBS. For example, PERT and Gantt diagrams to identify deadlines and interdependencies between tasks.

Equip yourself with the right tools to gain flexibility and agility, but also to save time later on when managing the project.

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FAQ on the WBS method

What is a WBS in project management?

The WBS, or Work Breakdown Structure, is a hierarchical breakdown of a project into successive deliverables. Each element in the structure corresponds to an expected delivery, not a task. The result is a clear vision of what needs to be produced, at what level, and by whom.

What is the difference between WBS and Gantt?

The WBS structure breaks down the project into deliverables. The Gantt diagram, on the other hand, organises the tasks over time. The first structures the content of the work, the second plans the phases and their duration. They complement each other. And no, it's not a Gantt vs WBS battle: they work hand in hand.

Should WBS be used for all projects?

Not necessarily. If you're organising a team drinks party or an office move, there's no need to bring out the WBS structure. But as soon as there are several deliverables, varied resources and structured project management, the WBS becomes a precious ally. Even small, complex projects benefit.

How many levels are needed in a WBS?

There is no magic number. Generally, between 3 and 5 levels are sufficient. The aim is not to create a gas factory, but to have a structure that is clear, legible and useful for monitoring the work. Too much detail kills organisation.

Is it possible to create an agile WBS?

Yes, but with flexibility. In an agile project, the WBS structure can be used to map the major objectives or deliverables for each sprint or phase. It is then used as a compass, not as a fixed map.