Protect the team from overcommitting
As your organization communicates an inspiring vision often you will find team members as well as leaders seek to commit to more than they know they can deliver. As a consequence I often see teams delivering less instead of more.
As teams take on more stories or more features than they can deliver they are bringing more distractions into their commitment. When a team member switches context (moving from one incomplete story to another) you often find they lose 20% of their productivity due to various setup and teardown activities. A negative consequence of this is that a team taking on too much work will often complete LESS not more!
Use Historical Velocity
When teams make a commitment they should make that based on historical velocity. Is this sprint dramatically more than they have achieved in the past? If so you may ask the “what is different this sprint that would make it possible to reliably meet this commitment?” If your working with the team to develop a normal velocity you will find it’s usually a very good guide of what they can achieve.
While it’s common for the team to overcommit it’s also possible an outside leader is pressuring the team to add more to their commitment. If this is the case it’s critical to talk to that leader and help them understand the detrimental impact of context switching and how that will actually get worse results from the team in this current iteration. Instead they need to focus on ensure the highest priority items are completed first.