Resource Leveling: Optimizing Resource Allocation in Project Scheduling

PMBOK v8 Definition

Resource leveling is a technique in which adjustments are made to the project schedule to optimize the allocation of resources and which may affect the critical path. This technique adjusts the start and finish dates based on resource constraints with the goal of balancing the demand for resources with the available supply. Resource leveling is used when shared or critically required resources are available only at certain times or in limited quantities, are overallocated (such as when a resource has been assigned to two or more activities during the same time period), or when there is a need to keep resource usage at a constant level.

Why It Matters for the Exam

Resource leveling appears frequently in PMI exam questions testing your understanding of schedule optimization under resource constraints. You will encounter this concept in questions about the Schedule Management Knowledge Area, particularly in scenarios where resources are overallocated or limited. The exam tests your ability to distinguish resource leveling from resource smoothing and to recognize when leveling is required before schedule baseline approval.

Key Points to Remember (for the exam)

• Primary Purpose: Balances resource demand with available supply by adjusting start and finish dates based on resource constraints
• Critical Path Impact: Resource leveling may affect the critical path (unlike resource smoothing, which does not)
• Triggers for Use: (1) Shared or critically required resources available only at certain times or in limited quantities, (2) Resource overallocation (assigned to multiple activities simultaneously), (3) Need to keep resource usage at a constant level
• Schedule Adjustment: Adjusts start and finish dates—this is the core mechanism of the technique
• Common Confusion: Resource leveling can change the critical path; resource smoothing does not change the critical path
• Baseline Requirement: Schedule must be analyzed to identify conflicts with logical relationships and determine if resource leveling is required before the schedule is approved and used as a baseline
• Resource Calendar Dependency: Resource calendars identify working days, shifts, and availability periods—essential input for determining if leveling is needed

Typical PMI Exam Example

A project manager has assigned Sue to work on Activity A (16 hours) and Activity B (8 hours) during the same 3-day period. Sue is overallocated because she cannot work 24 hours in 3 days. After resource leveling, Activity A is rescheduled to start on Day 1 and Activity B on Day 2, balancing Sue's workload to 8 hours per day. The critical path may shift as a result of this schedule adjustment.

PMI Exam Traps

• Trap: Thinking resource leveling never changes the project duration

  • Reality: Resource leveling may affect the critical path, which can extend the project duration

• Trap: Confusing resource leveling with resource smoothing

  • Reality: Resource leveling adjusts dates based on resource constraints and can change the critical path; resource smoothing adjusts activities without changing the critical path

• Trap: Assuming resource leveling is only for overallocated resources

  • Reality: Resource leveling is also used when resources are available only at certain times or in limited quantities, or when keeping resource usage constant is needed

• Trap: Believing resource leveling is performed after baseline approval

  • Reality: Resource leveling is analyzed before the schedule is approved and used as a baseline

Important PMI Connections

Quick Review Questions

1. A resource is assigned to two activities occurring simultaneously. Which technique adjusts start and finish dates based on this resource constraint and may affect the critical path?

2. What is the key difference between resource leveling and resource smoothing regarding the critical path?

3. When should resource leveling be performed relative to schedule baseline approval?

4. Name three situations that trigger the use of resource leveling according to PMBOK v8.

5. A project manager needs to keep resource usage at a constant level across the project. Which technique should be applied?

PMBOK v8 Reference

Section 5 – Tools and Techniques (Resource Leveling, Figure 5-18)