Agile software development is the way we build software now. The general consensus on management of software development projects is that predictive planning approaches (e.g., Waterfall) are ill suited for the job. However, almost two decades after the release of the Agile Manifesto and the rise of Scrum as the most popular Agile framework, team velocity is still a point of confusion.
Some organizations are under the mistaken idea that they can “buy” Agile-Scrum software development services à la carte based on team velocities. Under this contracting model, service vendors offer prepackaged teams rated at some velocity. Based on that velocity, the organization could then pay for a certain amount of that team’s time to complete predefined tasks. This arrangement treats Scrum teams as plug-and-play units of development capability. This mentality is evidence of a fundamental misunderstanding of Agile and Scrum, of what teams require to be effective, and of the concept of team velocity itself.
What is Team Velocity?
The concept of team velocity is not officially part of the Scrum framework. It is a best practice for estimating Development Team throughput. More specifically, it is the rate at which the Development Team, in collaboration with the other members of the Scrum Team (i.e., the Product Owner and ScrumMaster), delivers discrete items of functionality that are finished, tested, and accepted during an iteration/Sprint. The Scrum Team documents requirements for those items as User Stories and tracks and orders User Stories in the Product Backlog.
Rather than simply counting the number of completed stories at the end of a Sprint, the Scrum Team determines its velocity by adding together story points from every story completed during the Sprint. Story points form the basis for determining team velocity. Calculating team velocity allows Development Teams to estimate the amount of capability (value) they can deliver at a sustainable pace during a Sprint.
It is important to view team velocity results as data points along a trend, rather than as definitive stand-alone measures. In other words, to understand how much value a Development Team is capable of delivering, we need to look at velocity results from the previous two or three Sprints to get a sense of whether the latest result is part of a trend or an anomaly. Such anomalies often indicate issues requiring attention.
Like the concept of team velocity, story points are not part of the Scrum framework. The Development Team assigns story points to Product Backlog items (i.e., Epics and User Stories). Story points are heuristically-determined, numerical proxies representing the combination of perceived or estimated:
- User Story complexity, risk, and uncertainty
- Level of effort required to complete the User Story
This combination is often referred to as the “bigness” or “size” of a User Story. The Development Team estimates User Story points by “sizing” User Stories relative to each other. More complex User Stories typically require more time and effort to complete, thus earning more story points than less complex stories.
Story point estimation is not restricted to specific timeframes or meetings. It is part of a continual refinement of Product Backlog items by the Scrum Team that includes:
- Adding, updating, or deleting items
- Decomposing items into smaller items
- Adding details and estimating story points
- Ordering/prioritizing items
Five Key Team Velocity Concepts:
1. Only the Development Team estimates story points with input from the Product Owner and other relevant stakeholders. They are not determined by a chief engineer or some other senior authority as an estimation exercise prior to the establishment of Development Teams and the appointment of Product Owners.
2. Team velocity is specific to the team. Velocity cannot be used as a point of comparison between teams. Team X is not necessarily faster or able to attain a higher throughput than Team Y because they earned a higher number of story points during a Sprint. The story points upon which team velocity is based are specific to the relative sizing performed by the team on their particular backlog of User Stories.
- Individual team member productivity across the team
- Team cohesion, collaboration, and effectiveness
- Team skill set and experience mix
- Level of programmatic support (i.e., the factors that fall under the purview of program management)
- Empowerment and level of engagement of Product Owners
- The team’s familiarity with the business domain, technology mix, and enterprise architecture
- The amount of automation leveraged in building, testing, and deploying code
Thus, the makeup of the Scrum Teams and the environment or ecosystem within which they operate determine velocity. Team velocity is ultimately a proxy for the overall health of the software development program and organization. When team velocity stagnates or drops, the search for potential causes must be systemic as opposed to a hunt for individual culpability.
4. It is normal for team velocity to fluctuate. What should concern us are large fluctuations or downward trends in velocity. Changes in personnel, technology, organizational structure, etc. will affect development teams in different ways and to varying degrees.
5. Improving team velocity is not the goal! Improving team capabilities, practices, tools, and program support improves team velocity. Focusing on improving velocity results in attempts to game the system rather than systemic improvement.
Conclusion
Scrum Development Teams are composed of people. People are not machines calibrated to deliver a predetermined rate of output. Teams need time and stability to gel into highly effective teams. Helicoptering Scrum Teams, even experienced ones, in and out of tasks significantly degrades velocity except perhaps for the most mundane and menial tasks (In which case, why employ Agile/Scrum at all?). Decades of reducing people to resources allocated across Gantt charts has led many to also think of Scrum Teams as abstract productivity units. Scrum requires much more of us.
Last Updated on February 2, 2022