Story Points in Adaptive EVM for Agile Projects
PMBOK v8 Definition
Story points represent the relative effort or complexity of work items in adaptive approaches, based on the understanding that teams are typically better at comparing work items than predicting precise durations. In adaptive earned value management (EVM), effort can be expressed through story points, resulting in a calculation of earned value (EV) and planned value (PV) for different iterations based on the story points assigned to each user story. The PV is the amount of story points estimated for the user stories planned until a certain date (usually the end of the iteration), and EV represents the story points estimated for the user stories that are considered done at the end of the same iteration.
Why It Matters for the Exam
This concept appears frequently in PMI exam questions that combine agile/adaptive approaches with traditional EVM metrics. You will encounter it in situational questions where a project uses story points for estimation and you must calculate EV, PV, or interpret performance trends. The exam tests your ability to distinguish how EVM adapts when using relative sizing (story points) instead of absolute time-based estimates.
Key Points to Remember (for the exam)
- PV Definition in Adaptive EVM: Planned value is the amount of story points estimated for user stories planned until a certain date, usually the end of the iteration.
- EV Definition in Adaptive EVM: Earned value represents the story points estimated for the user stories that are considered done at the end of the same iteration.
- AC Definition in Adaptive EVM: Actual cost is related to the costs for the team working on the user stories during the iteration, usually derived from working hours.
- Key Distinction: Story points reflect relative effort or complexity, not absolute time—this changes how you interpret EVM calculations.
- Common Confusion: Confusing story points with hours/days—story points are relative comparisons, not time estimates.
- Calculation Basis: EV and PV are calculated based on story points assigned to each user story, not on hours worked.
- Performance Measurement: AC has no upper limit; whatever is spent to achieve the EV will be measured.
Typical PMI Exam Example
An agile team plans 50 story points for a two-week iteration. At the end of the iteration, the team completed 40 story points. The team's actual cost (based on working hours) was $12,000. What are the PV, EV, and AC values for this iteration?
- PV: 50 story points (planned)
- EV: 40 story points (completed)
- AC: $12,000 (actual cost from working hours)
PMI Exam Traps
- Trap: Using hours instead of story points for PV and EV calculations in adaptive projects.
- Reality: PV and EV are based on story points assigned to user stories, not hours worked.
- Trap: Assuming AC is based on story points.
- Reality: AC is derived from working hours and costs for the team, not from story points.
- Trap: Confusing story points with absolute time estimates.
- Reality: Story points reflect relative effort or complexity, not precise durations.
- Trap: Thinking EV cannot exceed PV in adaptive approaches.
- Reality: EV measured cannot be greater than the authorized PV budget for a component, but story points completed can be compared to planned story points.
Important PMI Connections
| Related Concept | Relationship Type | Exam Attention Point |
|---|---|---|
| Planned Value (PV) | Direct calculation input | PV uses story points planned until a certain date (usually end of iteration) |
| Earned Value (EV) | Direct calculation input | EV uses story points for user stories considered done at end of iteration |
| Actual Cost (AC) | Performance measurement | AC is derived from working hours/costs, not from story points |
| Performance Measurement Baseline (PMB) | Baseline reference | Total PV for the project is also known as budget at completion (BAC) |
Quick Review Questions
- In an adaptive project using story points, what does planned value (PV) represent at the end of an iteration?
- How is actual cost (AC) determined when using story points for EVM calculations?
- Why can't story points be directly converted to hours or days for EVM calculations?
- What is the relationship between EV and the authorized PV budget for a component?
- In adaptive EVM, what does earned value (EV) represent at the end of an iteration?
PMBOK v8 Reference
Section on adaptive approaches in earned value management, as referenced in The Standard for Earned Value Management, p. 91. Also referenced in the glossary definitions for earned value (EV), effort, epic, and estimate.
Note: This article is based on PMBOK v8 content provided in the context above. For complete understanding, refer to the full PMBOK v8 Guide and The Standard for Earned Value Management.