An Ultimate Guide to Resource Breakdown Structures: Step-By-Step Process and Example

Sarah M. Hoban

Last updated on Mar 31, 2025

QUICK SUMMARY

Effective resource allocation can be the difference between a successful project and one that goes over time and over budget. A resource breakdown structure helps make sure your resource allocations solve problems, rather than creating them. Here's how to build an RBS.

TABLE OF CONTENTS What is an RBS? Why is It Important? Benefits What to Include RBS vs. WBS How to Create an RBS Tools Best Practices Example

Deploying the appropriate people and materials in the context of available time and budget is the crux of successful project execution. The resource planning process, particularly the resource breakdown structure, is a valuable tool to help you think through who and what you need to fulfill project requirements effectively.

In this article, you’ll learn how a resource breakdown structure categorizes and keeps track of project resources. We’ll also explain how to create a resource breakdown structure that you can share with project stakeholders.

What is a Resource Breakdown Structure?

A resource breakdown structure (RBS) is an organizational tool used to document and categorize the people, materials, budget, and time needed for project completion. Project managers should ideally develop an RBS during the project planning phase to evaluate how many team members—with what skill sets—are needed to execute a project before it begins.

At its most basic, an RBS is a list of resources for your project. An effective RBS acts as a visual hierarchy to break down resource requirements into increasing levels of detail that align with project requirements.

Why is an RBS Important in Project Management?

An RBS is an important project management tool that supports the project resource management process. An RBS:

Identifies necessary resources to support project activities
Highlights resource constraints before they become a bottleneck to project execution
Serves as an input for refining project timelines and project cost estimates
Gives you a baseline from which to make resource allocation decisions throughout the project lifecycle

Benefits of a Resource Breakdown Structure

Using an RBS to support resource planning offers several benefits:

Improved resource allocation: Once you’ve documented the resource needs for your project, you can compare that information with resource availability and resource utilization to assign project tasks to team members during the project planning phase. During project execution, you can monitor performance and make real-time adjustments as needed.
Easier budgeting and financial tracking: Visually organizing resources with an RBS makes it easier to forecast and optimize project costs. As the project progresses, you can keep track of who is performing project work and the associated costs.
Better risk management: By forecasting resource needs for your project, the RBS lets you identify, monitor, and take action to address any emerging project risks, making it more likely that you will overcome these risks to achieve project success.
Fewer resource bottlenecks and conflicts: Comparing the RBS’s picture of resource demand with available capacity allows you to adjust staffing levels and keep the project team engaged.
Motivated team members: Optimizing resource allocation ensures that team members work on project tasks that align with their skill sets and interests without risking overwork and subsequent burnout, improving performance.

What to Include in a Resource Breakdown Structure

Before we walk through how to create an RBS, let’s take a look at the different resource categories that you should include to enhance efficiency:

Human Resources

Human resources, or labor, are the personnel required to complete a project. Since so much of project management is people management, this category should take up most of your attention as a project manager.

Within the human resources category, differentiate by types of roles and/or levels of seniority (e.g., senior engineer, junior designer) as you craft your resource management plan. Doing so will streamline staffing requests, inform your budget, and improve delivery by better aligning types of resources with required project work.

You should also distinguish in-house employees from external contractors hired for specific tasks or functions, given the differential cost profiles for these resources.

A screenshot of Resource Guru's people profiles, which shows am employee overview, including a person's picture, email, job title, time zone, invitation status, phone number, notes, whether they are a contractor or employee, department, skills, if they are bookable, and their normal availability. In another time, the user can view an employee's assigned projects and clients. — *Resource Guru's people profiles centralize employee skills, roles, and availability, enabling seamless allocation of human resources.*

Material Resources

Material resources are the physical resources that you need to complete a project, such as equipment and other supplies. For digital projects, this might include things like software or domain licenses, as well as hardware or office supplies.

When negotiating with vendors to procure material resources, keep in mind that you may be able to apply them across other projects in your portfolio to save on costs.

Financial Resources

Tracking financial resources, or your project budget, is essential to managing other types of project resources effectively.

The RBS is a useful tool for understanding resource demand and associated costs. If you know which team members you intend to use on your project, how much time you need them, and their hourly rate, you can use that information to formulate a project cost estimate.

Integrating project cost controls is a resource management best practice.

Time-Based Resources

In addition to tracking costs, an RBS tracks the time needed to complete your project. If you understand how much time each resource must dedicate to fulfilling project activities, you can use that information to develop your project schedule and manage tasks.

A screenshot of Productive's visual timelines, which are sorted according to the team member and displayed as Gantt charts (colored bars representing different projects and vacation time spread over a condensed calendar representing the next 30 days.) — *Productive offers a visual timeline of scheduled work, tracking time entries, availability, and project assignments. This enables managers to allocate and adjust resources dynamically.*

Resource Breakdown Structure vs. Work Breakdown Structure

A work breakdown structure (WBS) is an organizational tool used for visualizing project deliverables and the work required to complete those deliverables. Using a WBS in tandem with an RBS paints a complete picture of what work must be completed and who is responsible for executing that work.

Both a WBS and an RBS are inputs into a RACI chart, which identifies roles and responsibilities for stakeholders across project tasks.

How to Create a Resource Breakdown Structure

Follow the steps below to create an RBS for your project:

1. Identify Required Resources

Consult with project stakeholders, your prior project experience, and any historical project data at your organization to determine what resources you need to execute project work.

2. Categorize Resources

Once you’ve identified the list of resources, categorize the list. Resource categories include human resources, material resources, financial resources, and time-based resources.

Breaking down resources into categories streamlines budget requests and ensures that you are budgeting and scheduling work appropriately.

3. Assign Resource Ownership and Responsibility

Take your categorized list of resources and drill down into further detail around roles, responsibilities, required skill sets, and associated costs.

For example, every human resource in your RBS should have an assigned hourly rate. Every material resource should have an acquisition cost and an operating cost.

4. Align the RBS with Your WBS

At this stage, you’ll want to cross-check your RBS against the WBS you’ve made for your project to ensure that each task has an assigned resource. Make sure that assigned team members are available and have the appropriate skills to execute project tasks.

5. Validate and Review the RBS

Review your draft RBS for completeness and feasibility. Then, validate with your stakeholders to ensure you haven’t missed any key details. Make any necessary adjustments to the RBS based on stakeholder feedback.

6. Distribute the RBS

Once it’s finalized, distribute the completed RBS to project stakeholders to ensure alignment and accountability for the proposed plan.

Resource Breakdown Tools

As you’re working to craft your RBS, keep in mind that there are a number of resource management tools on the market that can automate some of the legwork involved in the resource management process.

Check out our list of the best resource management software:

Resource Breakdown Structure Best Practices

Here are some best practices to keep in mind when developing an RBS:

Keep the structure clear and hierarchical: Including too much detail in your RBS may render it unwieldy or difficult to manage. Evaluate what level of information is necessary to manage project resources without introducing too much complexity.
Ensure the RBS aligns with project objectives: In documenting and categorizing your list of resources, review your RBS for alignment with the objectives established in your project charter. If the resources listed will not contribute to a successful project, ask yourself whether they are needed.
Gain stakeholder buy-in: If your team is not on board with the resources listed in the RBS, then it is not a useful tool. Gather stakeholder feedback to refine your RBS and make sure its contents are realistic.
Regularly update and refine the RBS as project needs evolve: Like any project artifact, the RBS should be a living document to facilitate real-time decision making. Keep it updated regularly to reflect changing project circumstances.
Integrate your RBS with project management software for better tracking: You can also integrate the RBS with your existing project management software to flag potential resource management issues before they arise.

Resource Breakdown Structure Example

Here’s an example of an RBS that you can consider for your own projects. Note that each resource listed is assigned a category, role, and associated cost:

An example of a resource breakdown structure. It is a chart with the Resource Category (Human Resources and Material Resources) along the side and categories, including Resource Type, Hourly Rate, Number of Hours, Acquisition Cost, Operating Cost, and Resource Cost along the top. In the Human Resources there are two resources: Senior Engineer and Junior Engineer. The Senior Engineer has an hourly rate of $200 and works 10 hours, making their resource cost $2,000. The Junior engineer has an hourly rate of $75 and works 30 hours, making their resource cost $2,250. In the Material Resources section there are two resources: Software Licenses and Servers. Software Licenses have an operating costs of $100/license multiplied by 20 staff, making a total resource cost of $2,000. The servers have a $5,000 acquisition cost and an operating cost of $250 per month over twelve months, making the resource cost $8,000. — *An example RBS chart that shows the associated costs for various human and material resources.*

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