Resource Smoothing: Adjusting Schedule Activities to Meet Resource Limits

PMBOK v8 Definition

Resource smoothing is a schedule optimization technique in which adjustments are made to the activities of a schedule model such that the requirements for resources on the project do not exceed certain predefined resource limits. In resource smoothing, as opposed to resource leveling, the project's critical path is not changed and the completion date may not be delayed. Activities may only be delayed within their free and total float.

Why It Matters for the Exam

Resource smoothing appears frequently in PMI exam questions that test your ability to distinguish between schedule optimization techniques. It is commonly tested in scenario-based questions where resource constraints exist but the project completion date is fixed, requiring you to identify which technique maintains the critical path.

Key Points to Remember (for the exam)

• Critical Path Remains Unchanged: Unlike resource leveling, resource smoothing does not change the critical path. The project completion date may not be delayed.

• Float Constraint Only: Activities may only be delayed within their free and total float. No activity can be pushed beyond its available float.

• Resource Limits Are Predefined: The technique adjusts activities so that resource requirements do not exceed certain predefined resource limits.

• May Not Optimize All Resources: Resource smoothing may not be able to optimize all resources. Some resource constraints may remain unresolved.

• Key Distinction from Resource Leveling: Resource leveling may affect the critical path and delay completion; resource smoothing does not.

Typical PMI Exam Example

A project manager has a schedule with activities on the critical path and several non-critical activities with positive float. During execution, the project manager discovers that two non-critical activities require the same specialized technician during the same week, exceeding the available resource limit. The project manager adjusts the non-critical activities within their available float to resolve the conflict without delaying the project completion date.

Question: Which technique is the project manager applying?

PMI Exam Traps

• Trap: Confusing resource smoothing with resource leveling

  • Reality: Resource smoothing does NOT change the critical path; resource leveling MAY change the critical path

• Trap: Assuming resource smoothing can resolve all resource conflicts

  • Reality: Resource smoothing may not be able to optimize all resources

• Trap: Thinking resource smoothing delays the project completion date

  • Reality: The completion date may NOT be delayed; activities are only delayed within float

• Trap: Confusing resource smoothing with schedule compression techniques (crashing or fast tracking)

  • Reality: Resource smoothing adjusts activities for resource limits; compression techniques shorten the schedule

Important PMI Connections

Quick Review Questions

1. A project has resource constraints but the sponsor requires the project to finish on the original completion date. Which schedule optimization technique should the project manager use?

2. What is the maximum amount an activity can be delayed when applying resource smoothing?

3. True or False: Resource smoothing can change the project's critical path.

4. A project manager applies resource smoothing but finds that some resource conflicts remain unresolved. Is this expected? Why or why not?

5. How does resource smoothing differ from resource leveling regarding the project completion date?

PMBOK v8 Reference

Section 5.2.2.3 - Schedule Optimization Techniques (Resource Smoothing)