Guide to Work Breakdown Structure

Projects are getting bigger and increasingly complex. Without a proper way to break down the work, project managers would struggle to know where to start when it comes to planning. Work Breakdown Structures are a powerful tool the project managers use to divide up their projects into actionable chunks to build a realistic and achievable plan for project success.

In this blog, we will run through what a Work Breakdown Structure is, why it is important and how to start building one for your project!

What is Work Breakdown Structure (WBS)?

The Project Management Institute defines the Work Breakdown Structure as the: ‘deliverable oriented hierarchical decomposition of the work to be executed by the project team’ (PMBOK Third Edition, 2004).  

WBS helps visualise the hierarchical breakdown of work within a project into more easily manageable chunks. It is a powerful tool that integrates project scope, cost and schedule baselines to ensure project plans are aligned, accurate and realistic.

A WBS breaks down work within a project into distinct levels, with typical WBS ranging from 4 to 6 levels depending on the size and complexity of the project.

The Two Types of Work Breakdown Structure

There are two types of WBS, deliverable-based and phase-based WBS. The more common of the two is deliverable-based WBS and the key difference between them is how Elements are identified in the first level of the WBS. A deliverable-based WBS clearly illustrates the relationship between the project deliverables and the scope of the work to be executed. A phase-based WBS typically divides the first level into five elements (following the traditional phases of a project) and deliverables are further identified within those specific phases.

Just like most things in project management, WBS is no one-size-fits-all tool. Every project is unique and whether you use deliverable-based or phase-based WBS, the main goal of a WBS is to simplify project planning and make projects more manageable. The best WBS to suit your organisation is simply the one that makes your projects more manageable. 

Benefits of Work Breakdown Structure 

There are many benefits to an effective WBS, some include:

Ensuring project deliverables and tasks are clearly defined, visualised and organised

A WBS helps a project plan move from a vague sketch to a clearly defined structure. When project deliverables and tasks are defined, only then can their different subtasks, dependencies and allocations can be made in the most time and cost-effective manner. This also makes sure that no tasks slip between the cracks and are forgotten.

Improves project transparency and accountability 

With clearer task definition comes clearer task ownership and accountability. If all team members and stakeholders are aware of their specific roles and responsibilities within the project plan, decisions can be made faster and issues can be escalated to the right people.

Facilitates better communication and collaboration

A well crafted WBS gives all team members and other stakeholders the transparency and clarity to know exactly different factors interact with one another within the project. This helps facilitate better communication and collaboration between all key stakeholders as they know exactly what needs to be done, what is expected and how all teams and tasks are interconnected and potentially interdependent on one another.

Enhances project planning

A detailed WBS requires integrating and managing your project schedule management, cost management and resource management activities. When tasks, deliverables and their ensuing dependencies are clearly defined, project managers, can then make more accurate estimations on the project schedule, cost and resources. A better plan gives a better chance for project success. 

Simplifies project monitoring and management

When paired with effective project management software, WBS helps make project monitoring and tracking much easier. Instead of having to manually input and keep up with every task, WBS structures can be imported into the project management software, tasks automatically allocated and project progress can be tracked in real-time. 

Reduces chances for scope creep

Scope creep is one of the biggest challenges of project management. Without proper definition and clarity, projects can keep on growing beyond their initial scope and result in budget and schedule overruns. WBS helps clearly define the scope of the project in written terms and helps identify risks that can potentially lead to scope creep.

Improves risk identification and management

With all the tasks and dependencies clearly mapped out, a WBS can help project managers identify potential risks they may have overlooked. With greater clarity, project managers can better identify potential risks and set up better mitigation plans to manage the potential impacts of those risks.

Basic Guidelines For Work Breakdown Structures

There are plenty of benefits that come with a proper WBS but it all starts from doing it right. Here are some foundational guidelines to follow by when building your WBS.

1. Have clear definitions and direction

A WBS is all about clarity. Make sure that the parameters of the project – from its scope and costs are clearly defined and agreed upon before developing your WBS. You don’t want to end up having to adapt and edit your entire WBS if there are any project scope tweaks in the early stages.

2. Make sure it is completely exhaustive

A proper WBS describes the complete work of the entire project. Explore and clearly define absolutely everything that will happen in the project.

3. Apply the 100% rule

The 100% rule states that the highest two levels of the WBS should encapsulate 100% of the work in the project within the authorized scope. Lower levels of the WBS elements describe the activities in more detail but should amount to the same amount of work outlined in the higher two levels.

4. Utilise the right level of detail

There is a difference between being detailed and being excessive. While a WBS should be completely exhaustive in identifying tasks and deliverables, it should provide the necessary level of detail to help manage, plan and control the project without overburdening project managers with excessive information.

5. Follow the decomposition rule

The PMBOK definition clearly includes decomposition within the definition of WBS. Decomposition refers to the technique of subdividing the project scope and deliverables into further manageable components. The decomposition rule suggests that each element of the WBS should decompose into at least two ‘children’ or lower-level components. Each ‘child’ should only have one parent and must not be connected to multiple higher-level elements.

6. Apply Change Control

Changes happen all the time within projects. That’s why it is critical to establish the right processes to help manage different types of changes as they occur. Some changes may include changes between different branches or elements within the WBS, between the WBS and management reserves outside of the WBS and between the WBS and the external client where changes to scope can be authorised through the project change control system.

How to make a Work Breakdown Structure

Here are a few quick steps to making a WBS.

Step one: Gather critical documents and define deliverables

Get together all the documents you need to help clearly identify and define project deliverables, tasks and responsibilities. Some key documents include the initial Project Charter, Scope Statement and Project Management Plan.

Step two: Identify key team members

Once you know all the tasks and expected deliverables, it’s time to find the right people to get the job done. Identify who may be the appropriate team members to complete the different tasks and make sure they are aware of their responsibilities. This will also help clearly define accountability and the decision-making hierarchy during the project.

Step three: Define the Level 1 elements

Following the 100% rule mentioned above, identify the core elements that capture 100% of the work within the project. Make sure to verify whether 100% of the project scope is captured and in line with the agreed-upon project scope.

Step four: Further decompose Level 1 elements

This is where you further decompose your Level 1 elements into smaller manageable chunks. Still applying the 100%, make sure that the tasks and elements are mutually exclusive from one another and can be easily assigned to a single member or team. The critical question to ask at every stage is, ‘ Will further decomposition improve project management?’. If no, then your WBS is complete.

Step five: Create your WBS Dictionary

The WBS Dictionary is a narrative description of the work covered in each element of the WBS. The lowest level element is called a work package and each work package clearly outlines the task, expected deliverable, assigned responsibility, milestones and more. The level of detail should correspond with the 100% rule and cover the agreed-upon project scope.

Step six: Create your WBS visualisation

There are many different ways you can visualise your WBS in chart form. Some of the most common charts include the WBS structure list, tree diagram, and Gantt chart. Export or enter your WBS into whatever format that is supported by your pre-existing project management software to allow for further scheduling and project tracking.

Key terminologies in the Work Breakdown Structure

You may have been reading the above section and come across a few items and terms that needed a bit more elaboration. Here are some of the key concepts and terminologies you should know regarding WBS.

WBS Element

A WBS Element is any singular component within the WBS diagram. They are typically divided into two categories – parent and child. The ‘parent’ element is a higher level element that can be further decomposed into two or more lower-level elements known as the ‘child’ element. The ‘child’ element is characterized by its single association to a ‘parent’ element.

Work Package

A Work Package is the lowest level of any branch within a WBS. It is a defined segment of work that produces a specific deliverable. The Work Package replicate the level of detail required for the project, small enough to allow project managers to effectively plan, manage and control the work without overloading them with excess data.

Planning Package

The Planning Package is another type of Work Package that encapsulates a defined scope of work and acts as a ‘ temporary holder’ for cost, time and other estimations. This is required as sometimes work within the project is dependent on other moving parts within the project and needs to be decomposed further at a later date. At the appropriate time, the planning package is further broken down into separate work packages, leading to the commencement of that specific scope of the project.

Control Account

The control account is a monitoring and control tool within the WBS. It groups work packages together and monitor their progress by integrating the scope, budget, actual cost and schedule changes occurring at that specific point. While each control account may include one or more work packages, each work package should only have one associated control account. The one responsible for managing and monitoring the control account is commonly known as the Cost/Control Account Manager or CAM.

WBS Dictionary

The Work Breakdown Structure Dictionary is the accompanying document to the WBS that describes each element within the WBS. A typical WBS dictionary will include:

  • A WBS number (a unique code that identifies the specific element)
  • A description of the element
  • Requirements to start the work package
  • Associated activities and milestones
  • Defined responsibilities and roles for those who will perform and manage the work
  • Defined deliverables and the end receiver of the deliverables
  • The estimated duration, resource and cost of the work package
  • How progress will be measured

WBS Levels

The WBS level is the established hierarchical structure of the Work Breakdown Structure. The highest level of the WBS is often dubbed level 0. Levels 1 and 2 identify the core elements and should encapsulate 100% of the work within the project as per the 100% rule. Depending on the size and complexity of the project, the amount of WBS level may vary. Projects typically run between 4 to 6 WBS levels.

The Work Breakdown Structure and Project Management Software

Nowadays, most project managers are using some form of project management software to manage their projects. The great thing is that many project management software is designed to accommodate your WBS. Here are some key  features you should look out for in your project management software

Feature one: Task breakdown

Your project management software should be able to easily break down tasks into subtasks within the system itself. It should enable project managers to easily allocate task owners, set priorities and assign duration periods to each task to inform the greater project schedule.

Feature two: Visualisation capabilities

The WBS is often visualized through different types of charts. If your teams use Gantt charts, make sure your software includes Gantt chart tools that you can easily modify to your needs. This is particularly handy when visualizing dependencies and giving your teams easy to follow snapshots of project timelines.

Feature three: Collaboration tools

It would be a shame to have all your tasks and responsibilities easily visualised but not properly integrated with all your other project management tools and processes. An effective project management software will allow you to easily collaborate within the software itself without having to either manually input data from different applications or have data gaps between the different platforms.

Feature four: Real-time monitoring and dashboards

Your WBS may have hundreds of smaller work packages. Keeping up to date and monitoring all of them, even with great project management software, would be a time-consuming task without real-time monitoring and smart dashboards that can give you a quick overview of work progress. 

WBS involves integrating cost management, schedule management, resource management and many other functions of project management together. Often, teams use multiple platforms or apps to capture data for different functions. Making sure that your project management software can integrate and link your WBS code across all your platforms significantly reduces the time wasted and potential human error risk that comes with manually linking up to work packages across different platforms.

Bring out the full potential of your Work Breakdown Structure with pmo365

Are PPM experts are all advocates for an effective WBS. But bringing out the full potential of your WBS and optimising the amount of time that comes with managing and controlling it is not an easy feat. If you want to have a look at how we help take your WBS to the next level, particularly in regard to project schedule management, have a read here. If you want to see an intuitive WBS tool in action, make sure to book a free trial with our PPM experts today!

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