Numbers from the Fibonacci sequence (Wikipedia) are often used in Agile methodologies for estimating the amount of effort or complexity a task will need to be completed. These story points, which are really Fibonacci sequence effort values, are assigned through a technique called Planning Poker. It can also be used by individuals to estimate story points for their own tasks.

About the Fibonacci sequence

Numbers in a Fibonacci sequence follow a pattern where each number is the sum of the two preceding numbers.

For example: 0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, 233, 377, 610, …

It’s used for estimating effort or complexity because the numbers have enough of a numeric difference between them to make them useful for assigning work values that are in a ballpark of what effort we think it might take to complete . Numbers that are too close to one another, like 8 or 9, are impossible to distinguish as estimates, whereas numbers like 5 or 8 are easier to map effort to.

How you should use Fibonacci sequence effort values

Story points are a measure used to estimate the effort (or complexity) of individual user stories (ie tasks) within a software development project. The higher the number, the more complicated it or time consuming it is. They help prioritize work and determine resources needed.

Effort values for you to use

1 – Trivial, and can be finished within a day (e.g. a label change)

2 – Simple, and can be completed within 1-3 days (e.g. adding new fields, basic data processing)

3 – Can be completed within a week for 1 person

5 – Can be completed within a sprint for 1 person

8 – Bigger than can be completed within a sprint for 1 person

13 – Too big to be completed within a sprint with more than 1 person

Are these the only criteria for Fibonacci effort values?

Not at all! If you search, you will no doubt find other criteria assigned to Fibonacci sequence effort values. Different types of work may have different values, however these should work for you to at least get started!