Fibonacci Sequence for Story Points: Why do we use them? #Agile #Scrum #Kanban #Python #JavaScript

Why Fibonacci Sequence is Used for Story Points
Story points are a relative measure used in Agile methodologies to estimate the complexity, effort, and risk associated with a task or user story. The Fibonacci sequence (1, 2, 3, 5, 8, 13, etc.) is often used for estimating story points because it naturally introduces a non-linear progression, which is useful for several reasons:

Acknowledges Uncertainty: As the numbers grow, the gap between them increases (e.g., the gap between 1 and 2 is 1, but between 5 and 8 is 3). This reflects the increasing uncertainty and complexity as tasks become larger or more complicated.

Encourages Discussion: The non-linear nature of Fibonacci numbers forces teams to discuss and debate the effort involved, especially when considering larger numbers. This can lead to better consensus and understanding of the task at hand.

Avoids Over-Precision: Fibonacci numbers prevent teams from falling into the trap of over-precision, where they might be tempted to estimate too finely (e.g., assigning a task a 7.5 or 8.2). The use of Fibonacci numbers keeps estimates rough and relative.

Prioritization: The sequence helps teams differentiate between the effort required for smaller and larger tasks more effectively. This helps in prioritizing work based on the level of effort and value.

How Story Points Translate into Time
Story points do not have a direct, universal translation into time because they are a relative measure of effort, not a measure of duration. However, over time, teams develop a "velocity," which is the average number of story points they complete in a sprint (e.g., two weeks). This velocity can help in translating story points into time, but it varies from team to team.

Here’s how the process generally works:

Team Velocity: After a few sprints, a team can calculate its velocity, which is the average number of story points completed per sprint. For example, if a team completes an average of 30 story points in a 2-week sprint, their velocity is 30 points per sprint.

Estimate Duration: With the velocity known, the team can estimate how long a set of stories will take. For instance, if a backlog has 90 story points worth of work, and the team's velocity is 30 points per sprint, it would take approximately 3 sprints (or 6 weeks) to complete that work.

Individual Stories: While velocity helps estimate the duration for a batch of stories, translating a single story point into hours is not recommended. However, a rough estimate might be developed over time based on team experience. For example, if 1 story point tends to translate to about 4 hours of work on average for a particular team, that might be used as a very rough guide.

Variability: It's important to note that the translation of story points to time can vary depending on the complexity, risk, and uncertainty associated with the tasks. One sprint’s 5-point story might take longer than another sprint’s 5-point story due to differences in the nature of the work.

Key Takeaways
Fibonacci sequence: Used to represent the uncertainty and complexity of tasks, encouraging discussion and avoiding over-precision.
Story points: Represent a relative measure of effort and complexity, not time.
Velocity: Averages the number of story points completed in a sprint, helping to estimate how long a set of stories will take, but not a precise translation to hours or days.
This approach helps Agile teams manage uncertainty and complexity while focusing on delivering value rather than exact time estimates.

This was entirely AI generated.

[christiansnyman]

We just stick to hours as it feels more closer to planet earth. Using fibonacci makes no sense, 21 hours vs 21 story points. Hours just feels more concrete and you can easily track back on time spent. If someone told me they spent 21 story points on a project, I have no idea how long they actually spent?

[DavidAldridge]

Ratio and a curve makes more sense to humans