Extending Scrum with Kanban practices

In this post I’ll describe three Kanban practices that can be used to improve a Scrum team’s overall performance:

 

Explicit states and policies

A usual Scrum sprint board has three columns: TODO, WIP and DONE. Also, most Scrum teams have explicit policies for the Definition of DONE and the Definition of Ready. The problem is that the WIP state of this kind of board is a black box: anything can happen there. It’s a Kanban practice to define every state that a story must follow before reaching DONE. This approach helps the team to better organize themselves around a common development process and also to define explicit policies for each state transition. A common Kanban board has these columns: Backlog, Define tests, Design & Code, Run tests, UAT, DONE. Also, the team defines explicit policies for each transition, with very specific rules describing even which branch a story should be in a specific board state. Explicit states and policies gives the team a higher level of transparency, enabling them to find better optimization opportunities and standardization.

 

WIP limits

Another Kanban practice is limiting the number of stories that can be in each state at any given moment, forcing the team to focus on finishing things before beggining new ones. This approach also works great for Scrum teams! For example, we could set the following limits for each state: Backlog (8), Define tests (2), Design & Code (4), Run tests (2), UAT (1), for a team with 6 people (4 devs and 2 QAs). In this configuration it is expected that the Product Owner (or his team) will accept only one story at a time, because we’ve limited the UAT to 1. But the cool thing here is that if the Product Owner don’t accept it quickly, the team will eventually come to a halt, because all their states will reach its limits sooner or later. This simple rule greatly reduces the NOT DONE effect, making both the team and the PO a lot happier!

 

Cycle time measurement and optimization

One of the most important Kanban practices is measuring and optimizing the team’s cycle time, which is the average time that a story takes to go from the first to the last board state. A Kanban team strives to shorten their cycle time to the smallest value possible. This mindset also applies to Scrum teams: they can measure their cycle time during the sprint and always compare it to the last sprints, looking for ways to optimize it. The result of this optimization will be greater velocity, allowing the team to commit to more stories per sprint, what is wonderful!