Thank you, everyone, who has read my previous posts. I hope it added value and helped you in your day to day executions. This time, I thought let me explain about story points, which is the point of confusion among individuals. This post will help you understand What is the story point estimation? Why is it used? When is it used? and, why not to use Hrs or Days while estimating user-stories?
Let us start with What is story point? It is a unit of measurement. What do we measure with this unit? the user-story.
Why do we measure user-story in story points?
Let me narrate a story to you, and on this journey, you will get answers to all questions mentioned earlier.
So here it goes, in a family, a father gives a work to his son, daughter-in-law, and grandson. The work is to move bricks lying in the garden to the terrace garden and father tells his son, this activity is funded by your mother. The daughter is going to facilitate the activities.
Mother asks the father , how much will you charge as a team? father says “hold on, I will come back” .Father ,his son ,daughter-in-Law, and Grandson goes to the garden ,name one brick as brick 1 , moves few steps and picks up another brick and name it to brick 2 .Father asks his son, to hold brick 1 and hold brick 2 in another hand.
Father asks ” dear son tell me what do you think about both the bricks?” son says “dad, brick 2 is heavier than the brick 1”. Father asks how much heavier? Son says for that I should use a weighing scale. Father replies,” that is not required, just tell me roughly, how much heavier?”. Son gets the message, he says “dad brick 2 is roughly double the brick 1”. They all checked and agreed to label brick 1 as H and brick 2 as 2H.
Father asks, “how many bricks can they move in 1 hr?”. They replied, “it looks like brick 1 and brick 2 are doable”. They ask the father,” would not you want to know how much time it will take us to do this work, individually?”. They said ,” based on our answer ,you can ask money from mom”. Father says,” you can decide as a team who would do what”. As of now ,let us not spend time finding out hrs or days , a rough idea about comparative weights is sufficient enough to charge. So father goes back to the mother and tells how much they are going to charge to move 2 bricks”.
Just before starting this work, son, daughter-in-law and grandson estimate roughly about the time it will take them. According to grandson, a smaller brick will take him 120 minutes and bigger brick will take him 180 minutes. Son replies for him smaller will take him 30 minutes and bigger will take him 45 minutes. Daughter-in-law says for her smaller will take 40 minutes and bigger will take 50 minutes .Without spending too much time on strategizing, they start their work and slowly they figure out better ways.
In the course of shifting multiple bricks, the team becomes efficient in execution and they moved more bricks of larger sizes in 1 hr. They start achieving more in less time and getting more money in hand in lesser time. Grand mom gave proportional charges, and they made more money by saving on the cost of delay.
In this story, moving all bricks was the internal end product, which was executed incrementally, as 1 hr sprint. Mother is the CEO funding the internal product, Father is the product owner, daughter is the Scrum Master, rest were Dev team. Unit “H” is analogous to the SP (Story Point). One User-story is the movement of a single brick. Execution phase has multiple sprints, each sprint gets few bricks to move Hrs and days are the time units to execute multiple tasks in moving bricks.
So, with this narration, we understand that SP is required to estimate at a high level, it could be component interactions, layered interaction in Software development. As team evolves to a matured team, they figure out faster ways of delivering. Eventually, they become efficient and the team’s velocity increases, which is measured in SP and not in hrs or days of work done.
I hope, I have removed confusion by keeping the explanation simple enough. I would be happy If any day it helps you in the day to day activities. Thank you once again for reading this post. If you still have queries, I would be happy to clarify.