What is the difference between resource levelling and resource smoothing?

Resource levelling and resource smoothing are two project management techniques used to optimize the allocation of resources in a project. While they both deal with resource allocation, their objectives and methods are different.

Resource levelling focuses on resolving the over-allocation of resources. When resources are assigned more work than they can handle, resource levelling aims to redistribute the workload by adjusting the start and end dates of tasks, reassigning resources, or splitting tasks. The primary goal is to ensure that resources are not overburdened at any point in time. This might lead to changes in the project timeline, including possible extensions.

On the other hand, resource smoothing is used when the project manager wants to keep the project within its original time frame but with a more even distribution of resources. In resource smoothing, the task durations are not altered to the extent that they affect the project’s critical path. Instead, it involves adjusting the allocation of resources within the constraints of the project's timeline, so that resource utilization is as consistent as possible throughout the project. This often results in more efficient and predictable use of resources without affecting the project end date.