Monday, June 29, 2015

Agile Development: The Anatomy Of A Sprint

In my previous post in the Agile Development series I walked through the makeup of a sprint team. I explained the roles of Product, Dev, QA, Operations, and the Scrum Master. In this post I will go into detail on the anatomy of a sprint.


The first phase of the sprint life-cycle is planning. During the planning phase sprint velocity is determined, features are identified, features are estimated, and the backlog is created.

At it's most basic level the velocity of the sprint is determined by the number of points that were completed during the last sprint. When a sprint team first forms their velocity is very volatile. But as the team learns to estimate their story points more accurately there is less oscillation between the number of points completed sprint over sprint.

Determining which features are candidates for inclusion usually starts with product as the voice of the customer. Product will advocate for what the customer needs. The team will also identify what bugs and tech debt need to be addressed during the sprint.

Once the candidate features are identified the team will estimate the the level of effort for each story. At the formation of the sprint team a point system is determined and that point system is used for estimating work. The two most common point systems I've come across are using Fibonacci numbers (with 8 or 13 being the top end of a sprint) and using 1, 5, 10, 25, 50, and 100 as story points. Whatever your system of pointing there needs to be a way to determine small, medium and large stories.

There are many different estimating techniques but most teams I've seen use some sort of t-shirt size technique. They start by picking a story and assigning it an arbitrary point value. The rest of the stories are then pointed by determining if the story is larger or smaller than the initial story. When you have more than 3 assignments that you can use for point values you can get more granular and determine if the story is larger or smaller than the other stories in it's t-shirt size bucket.

Once the velocity is determined, potential features are identified, and stories are estimated you will be able to create your sprint backlog. Backlog creation begins by stack ranking the stories (taking dependencies into account) and cutting the sprint off after the last story that keeps the total number of sprint points at or less than the pre-determined sprint velocity.


The second phase of the sprint life-cycle is implementation. During the implementation phase the team meets daily at stand-up and goes over what they worked on yesterday, what they're working on today, and any potential blocking issues. When a blocking issue is identified it's up to the scrum master to try to unblock the team member. During the implementation phase the software should be developed, tested, and integrated.


The last phase of the sprint life-cycle is review. The review phase takes on two forms. The first is the sprint demo and the second is the sprint retrospective.

The sprint demo is the teams opportunity to showcase what they've built during the sprint. Sprint demos can actually be a very useful tool leading into the next sprint planning phase. Often when we think about planning with regards to software we think about what we're going to build from an architectural perspective. The problem with this line of thinking is that it typically leaves out integration, testing, and deployment. If we instead think about what we're going to demo during planning we'll have to take into account how we're going to demo it.

A note of caution about sprint demos. One mistake I've often seen teams make during sprint demos is to walk everyone through a bullet list of work that was performed. Walking others through a bullet list isn't a demo. If you find that your team is working on features that don't have a user facing component then figure out a creative way to tell the story of how what you worked on matters. Use an animation, a use case scenario, or maybe even a chart or some graphs to help illustrate what you worked on. 

The sprint retrospective is a mini postmortem. During the retrospective the team goes over what went well, what didn't go well, and what the team could have done better. The retrospective is a dedicated time for us to identify the issues that caused us to lose velocity, to call out our successes during the sprint, as well as identify what we could have done differently to have improved the sprint. Because the sprint review typically takes place before the planning of the next sprint we have an opportunity to make changes that give us a higher likelihood for success before the next sprint starts.

The retrospective IS NOT a finger pointing exercise. It's NOT a witch hunt or an opportunity to push blame around. The retrospective IS an opportunity to identify gaps in our planning, our process, or our estimates. The point of the retrospective is to maintain or increase our velocity.

Isn't there a phase missing?

You may be wondering where the "release" phase is. There isn't one. Releasing your software should be done as part of the implementation phase. Your sprint planning should account for what it takes to ship the software, if that's part of the definition of done for the sprint.

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