What is a story point? A story point uses the Fibonacci sequence (A series of numbers in which each number is the sum of the two preceding numbers. The simplest is the series 1, 2, 3, 5, 8, 13, etc.). A SCRUM team assembles and assigns points to user stories in the Product Backlog. Based on how many story points a team can complete in their sprint cycle that will determine the team’s velocity (Average number of points a team completes). Finally, based on velocity a SCRUM team can roughly estimate how long an item will take to create.
Some will say that a AGILE Story Point is a direct relation to time. Others will tell you that a story point is a relative number and that a point does not/should not equal a specific measurement of time. To be honest, both are correct.
Team 1 is assigned to create a dry erase pen. The pen itself is simple (as pens go) and has a cap. The team discusses and gives a point estimate of 2. This does not mean that the team can create the pen in 2 hours or 2 days but they simply assigned a 2 to create this pen.
Next the team is asked to build a squirt bottle to compliment the dry erase pen. The bottle is larger in size and has a removable cap. The difference is this item also has a spring loaded squirting applicator on top of the bottle that can screw on/off the top. After much discussion the team agrees to assign a point value of 8 to this item.
The level of complexity involved to create the bottle vs. the pen was greater. The time to create the bottle will take longer and there is more involved however we still don’t know how much time it will take to create these things. At this point we know the bottle has more points assigned than the pen.
Team 2, who is less experienced, is given the same exercise and assigns a value of 5 to the pen and a value of 13 to the bottle. There are several reasons why this occurs. One can be the experience level of the team. One team may have experience creating these items while the other does not. Experience level certainly plays a large role in how a team assigns story points.
At the end of the day story points is a relative number and can vary from team to team and even from one project to another. As a team matures they can more easily predict the length of a project based on what they know at any given time and what is currently in that product backlog.
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