Capacity planning and resource planning are often used interchangeably, but they answer different questions. Understanding the distinction — and using both — is one of the markers of an operationally mature organisation.
What Is Resource Planning?
Resource planning answers the question: who is working on what? It’s about assignment and allocation. Which people, teams, or skills are attached to which projects? Resource planning gives you a map of your workforce against your project portfolio.
Good resource planning surfaces things like: Sarah is allocated to three projects simultaneously; the UX team is a dependency on six initiatives; the platform team has no allocation for Q3 beyond BAU.
What Is Capacity Planning?
Capacity planning answers the question: can we deliver what we’ve committed to, given the people and time we have? It’s about supply vs demand. Even if you’ve assigned all your resources to all your projects, capacity planning tells you whether those assignments add up to a feasible plan.
A resource plan tells you everyone is assigned. A capacity plan tells you whether they’re assigned to too much.
Why You Need Both
Many organisations do one but not the other. Teams that resource-plan without capacity-planning know who is working on what but consistently miss deadlines — because they’ve committed to more than is achievable. Teams that capacity-plan without resource-planning have aggregate numbers that look fine at the portfolio level but have critical skill bottlenecks hidden underneath.
The complete picture requires both: who is on what (resource), and whether the total is feasible (capacity).
Where They Diverge
| Dimension | Resource Planning | Capacity Planning |
|---|---|---|
| Primary question | Who is on what? | Can we deliver? |
| Unit of measure | People / roles | Time / availability |
| Time horizon | Project duration | Quarter / sprint |
| Key output | Allocation map | Supply vs demand gap |
| Who drives it | Project managers | COO / operations |
Practical Integration
The best approach is to run them in sequence. Start with resource planning at the project level — assign people and teams to initiatives. Then roll up into capacity planning to validate the aggregate. If the aggregate shows overload, you go back to the resource plan and adjust.
In practice, this means your project management and capacity planning tools need to talk to each other — or live in the same system. When they don’t, you get the classic COO problem: resource plans that look complete and capacity plans that are never trusted because the data is always out of date.
