A Scrum team has worked hard to reach their sprint goal, but impediments have prevented...

At the sprint retrospective, the scrum master and development team should discuss why the team did not know the specialist was unavailable during the sprint. The scrum master should then set clear rules so situations like these can be avoided in the future.

It can be very distressing for a Scrum team not to reach its sprint goals. The scrum master should hold an evaluation meeting to discuss who in the team was responsible for discovering the specialist was not available, then make an improvement task for the next sprint.

The scrum master, as a servant leader, should always try to remain positive about the team's work. Even when team members’ make mistakes, there should be trust that everyone is doing their best. Engaged team members work more efficiently, and a sustainable pace is important for project success.

At the sprint retrospective, the Scrum team should reflect on how the past sprint has worked out. The scrum master should facilitate an open discussion to discover the root causes for the missed sprint goals and find a way to avoid similar situations in future sprints.