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Joe Mainwaring
Joe Mainwaring

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A Guide to Story Point Estimation

A story point is an arbitrary measure of effort required to implement a user story; it's a number that tells the team how hard the story is. β€œHard” can be related to complexity, unknowns, and/or effort.

Estimation Guidelines

  • Story Point values are based on a Fibonacci sequence (1,2,3,5,8,13,21,...)
  • Story point estimates should take into account technical complexity & effort to complete.
  • Story point estimates should account for the total effort to reach done, not just code complete. Both code review and QA testing can take considerable time and should be accounted for.
  • The lowest point value that can be assigned is 1, don't dabble in fractions of a story point.
  • Stories with an estimate larger than 8 should be refined and broken into multiple stories.
  • Time spent on different parts of the development process should be measured in hours & days.
  • When in doubt about the value of a ticket, play conservatively and go with the higher value.

Breakdown by Complexity

The table below is provided as a guideline for assessing story size by technical complexity.

Point Value Complexity Story Profile
1 None/Low Story is very narrow in scope or procedural in nature; requires little-to-no problem-solving skills. Low possibility that this story blocks other stories. Could be completed with relative ease by a new-hire.
2 Low Story has a small scope & may require some problem-solving or critical-thinking skills. Low possibility that this story blocks other stories. Can be completed with relative ease by junior-level engineer.
3 Low/Medium Story has a reasonable scope & requires some problem-solving skills by the engineer. Low possibility that this story blocks other stories. A junior-level who is knowledgeable in the feature should be capable of completing this story within a reasonable amount of time.
5 Medium Story scope has multiple conditions or states & requires a decent amount of problem solving to solution. Possibility that this story blocks work on other stories. Junior-level engineers may find this level of work challenging. Mid-level engineers who are knowledgeable in the feature should be capable of completing this story within a reasonable amount of time.
8 Medium/High Story scope is large or open ended (research spike) & requires significant problem solving skills to complete. Strong probability that this story blocks work on other stories. A mid-level engineer may find this level of work challenging. Senior-level engineers who are knowledgeable in the feature should be capable of completing this story within a reasonable amount of time.

Breakdown by Time Spent

The table below is provided as a guideline of the total effort put forth during Development, Code Review, and QA testing for a given point value. Duration values are shared as uninterrupted/distraction-free time; time spent on a ticket may exceed the value shown due to switching context throughout a given sprint (meetings, shifting priorities, etc)

Point Value Example Development Code Review QA Testing
1 Making a text edit 2 Hours 1 Hour 1 Hour
2 Implement a default profile image 1/2 Day 1 Hour 2 Hours
3 Implement white-label branding for the header of a page 1 Day 1/2 Day Up to 3 hours, could include triggering specific items/tasks, etc.
5 Construct the entire Change Password View (UI Only) 2-3 Days 1 Day Up to a 1/2 day, could include various browsers, roles, and/or permissions, etc.
8 Items within a list are based on a set of permissions and feature flags (full stack) 5 days 1-2 Days At least 1 full day of testing, compilation of all of the above

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