Story Points Vs. Hours: What's The Difference?
Understanding the estimation of work is fundamental for successful delivery within Agile project management. Story points and hours are two widely practiced approaches that most Agile teams use. These have a lot in common, though there are significant differences when it comes to application and philosophy. So, let's break down the basics and the points of distinction that will indicate whether to use either approach.
What Are Story Points?
Story points are a relative estimation technique used in Agile to evaluate the complexity, effort, and risk involved in completing a task or user story. Instead of focusing on time, story points assess the work based on:
- Complexity: How challenging the task is.
- Effort: The amount of work required.
- Uncertainty or Risk: Unknown factors that might affect completion.
Teams usually use a Fibonacci sequence (1, 2, 3, 5, 8, etc.) to represent the relative scale when assigning story points. A task with 8 points is more complex than one with 3 points, but not necessarily twice as hard.
What Are Hours?
The most traditional method is hours—an estimation of work based on the time taken to complete a task. It's linear and very straightforward; a team member simply assigns an expected number of hours or days to each task.
For example, if the construction of a feature is going to take 6 hours, the team works around it. This technique directly relates to the work schedule, making it suitable for short-term planning or industries that have been accustomed to time tracking.
Key Differences Between Story Points & Hours
- Focus
- Story Points: Focuses on effort, complexity, and risk.
- Hours: Focuses purely on time.
- Flexibility
- Story Points: Abstract and flexible, as they relate to different velocities of teams.
- Hours: Concrete and rigid, and often assume equal productivity.
- Measurement
- Story Points: Subjective and relative, so teams can estimate work together.
- Hours: Objective, but often based on individual estimates.
- Scalability
- Story Points: Good for long-term forecasting and managing uncertainty.
- Hours: Good for short-term, accurate scheduling.
When to Use Story Points?
- Agile teams that value collaboration and flexibility.
- When estimating work with high uncertainty.
- To establish consistent velocity metrics for sprint planning.
Story points allow teams to focus on the "big picture" rather than getting bogged down by exact time estimates.
When to Use Hours?
- In traditional project management environments.
- When tasks are straightforward and predictable.
- For projects where time tracking and billing are essential.
Using hours can work well for small tasks or when precise scheduling is necessary.
Can Story Points & Hours Work Together?
Yes, combining story points and hours can create a balanced approach. For example, story points can guide sprint planning, while hours ensure day-to-day tracking. This hybrid method leverages the strengths of both systems without compromising flexibility or precision.
Conclusion
The choice between story points and hours depends on your team's workflow, project requirements, and uncertainty about tasks. Hours may be beneficial for traditional approaches, while story points dominate Agile settings. Knowing these approaches' benefits allows teams to decide which would suit their goals in a particular project.
