As in life, things change.
One of the inevitabilities is that some day you may have a team member leave and you will find a replacement team member to fill that spot.
I would like to share something that could sneak up on a manager without being totally prepared for it. For me, when this happened, it was a big surprise. I decided to share this insight to avoid the same thing happening to you.
I had been spending so much time working on teaching the team how to work together, I had not really understood just how far they had come.
This soon changed after bringing on a new developer. A few iterations after having them start, we realized there was something wrong. They were not working out well.
After careful review and some discussions with some of the team members, we soon realized there was some open dialogue needed to make all the team members aware of how hard it could be for new members to integrate themselves and "form" with the existing team members. I had not realized just how far the team had progressed up to this point.
As a team, we modified some procedures slightly. We talked openly about how to make new participants feel welcome and removed obstacles for future team participants.
If you're reading this, hopefully you can see a situation like this coming and just be aware that it is something to consider and be prepared for if you manage or are responsible for an Agile Team.
Don't under-estimate just how far your team has come, especially when it comes to trying to integrate a new team member.