Cost Baseline: Approved Time-Phased Project Budget Excluding Reserves

PMBOK v8 Definition

The cost baseline is the approved version of the time-phased project budget, excluding any management reserves, which can be changed only through formal change control procedures and is used as a basis for comparison to actual results. Alternatively, the cost baseline may be the approved version of the time-phased initial project budget, excluding both contingency and management reserves, depending on organizational preferences or external influences. This baseline is a component of the project management plan and serves as the primary reference point for measuring cost performance throughout the project.

Why It Matters for the Exam

The cost baseline concept appears frequently on the PMI exam, particularly in questions about cost management, earned value management, and change control processes. Expect questions that test your understanding of what is included versus excluded from the cost baseline, how it differs from the project budget, and when formal change control is required to modify it. Exam questions often present scenarios where you must determine whether a change affects the cost baseline or simply requires reserve adjustment.

Key Points to Remember (for the exam)

• Definition Core: The cost baseline is the approved, time-phased budget used for comparison against actual results
• What It Excludes: Management reserves are always excluded; contingency reserves may be included or excluded based on organizational preference
• Change Control Requirement: The cost baseline can be changed only through formal change control procedures
• Two Possible Scenarios:
  • Scenario 1 (Left side of Figure 2-25): Cost baseline includes contingency reserve
  • Scenario 2 (Right side): Cost baseline excludes both contingency and management reserves
• Primary Purpose: Used as a basis for comparison to actual results (performance measurement)
• Relationship to Project Budget: The cost baseline is similar to the project budget but may vary depending on organizational preferences
• Update Process: Cost baseline updates involve revising the approved budget to accommodate changes that impact project financials

Typical PMI Exam Example

A project manager is reviewing the approved budget of $500,000, which includes a $30,000 contingency reserve and a $20,000 management reserve. During execution, a change request is approved that adds $15,000 to the scope. The project manager must update the cost baseline through formal change control. What is the revised cost baseline if the organization excludes contingency reserves from the baseline?

Answer: $485,000 (original $500,000 minus $30,000 contingency minus $20,000 management reserve = $450,000 baseline; add $15,000 scope change = $465,000; note that the $20,000 management reserve remains excluded)

PMI Exam Traps

• Trap: Confusing cost baseline with project budget

  • Reality: The project budget may include management reserves; the cost baseline excludes management reserves (and may or may not include contingency reserves)

• Trap: Thinking contingency reserve is always excluded from cost baseline

  • Reality: PMBOK v8 presents two scenarios—contingency reserve can be included OR excluded based on organizational preference

• Trap: Assuming cost baseline changes can be made without formal change control

  • Reality: Any change to the cost baseline requires formal change control procedures—this is a strict rule

• Trap: Confusing cost baseline updates with reserve adjustments

  • Reality: Reserve usage does not necessarily change the cost baseline; only approved changes through formal change control update the baseline

Important PMI Connections

Quick Review Questions

1. What two components are always excluded from the cost baseline according to PMBOK v8?

2. A project has a cost baseline of $1,000,000. The project manager identifies a risk that requires using $50,000 from management reserves. Does this change require updating the cost baseline through formal change control? Why or why not?

3. Your organization includes contingency reserves in the cost baseline. During execution, you need to use $25,000 from contingency reserves. How does this affect the cost baseline?

4. What is the difference between a cost baseline update and a project budget update?

5. The PMBOK v8 states that the cost baseline can be changed only through which specific process?

PMBOK v8 Reference

Section 2.7.3.1 - Cost Baseline (within the Cost Management knowledge area description) and Figure 2-25 - Budget Buildup Scenarios