Buffer your Sprints

2 minute read

My team has been successfully delivering software to our stakeholders using the Scrum framework. The fixed duration sprints and detectable/measurable velocity allows us to accurately forecast what we can deliverable each time…. mostly.

Plans are worthless, but planning is everything.

What we cannot account for during our Sprint Planning sessions is unplanned work, or, as the Agile Manifesto might word it, “Responding to change”.
Things break, hotfixes need to be deployed, one-pointer stories grow legs, shit happens.

Accepting new tasks into the sprint is known as Scope Change. The planned scope has been modified. If you look at your Burndown Chart, this is a vertical spike correlating to the number of points assigned.

Typically, the nature of such additions is that they are pretty important and urgent. Eisenhower’s Matrix for decision making tells us that if something is both urgent and important, then we must do it now.
This, however, pushes the remaining tasks a little further away, and potentially to the point of not being completed in the Sprint.

A mechanism that we have been using to help with such pain points, is including an explicit buffer in our Sprints.

Sprint Buffers

A sprint buffer is a very simple, but effective means of planning for unplanned work. It allocates a single task, storypointed to an average of the historical unplanned tasks (scope change in Jira lingo), which will then be used to bankroll unplanned work up to the buffer. Once the buffer has been reached, then you will need to make a call on how best to proceed.

In our case, I looked back over our last five sprints, and found that on average, the team accepted two points of unplanned work into each sprint. In those cases, we did not deliver all forecasted tasks.

In the next planning session, we added a task named “Buffer” into the sprint. The task was estimated at two points. We started the sprint as usual and left the buffer task in the TODO state until some scope change was encountered.

When unplanned work came in and needed to be actioned before the end of the sprint, we would categorise it and add it within the buffer.

A simple, straightforward, and transparent mechanism to budget for unplanned effort whilst achieving the forecasted deliverables of the sprint. Moreover, by tagging or labeling the incoming tasks, you will not only be measuring unplanned work, but you will also start to identify areas of consistent unplanned work. These are now opportunites for improvement.