Suggestions to handle the teams who are comfortable in their own way of working
I came across a scrum team where in they are typically following the below practices:
1. Adding the backlog items based on product owner wish neither estimating prior nor understanding what is the requirement
2. Adding stories anytime during the sprint time frame whenever new thing/important thing comes in
3. Not much bothered about spill overs
4. Team not sure about their capability to commit for the sprint
5. Not considering any metrics
Yet, they are comfortable with their deliverables and not willing to follow the theoretical practices
which scrum suggested and best practices from other agile frameworks.
Is it acceptable not following any prescribed practices and rules but still being continued as scrum team ?
Can we name them that they are following any other framework ?
Appreciate your comments in this situation
It is the Scrum Master's role to educate the teams and to show the benefit of following the Scrum framework practices. I guess what you describe is a team lacking maturity.
Can we name them that they are following any other framework ?
It doesn't sound like they are implementing Scrum nor is there a reason to suppose they follow another framework.
Are they providing the outcomes stakeholders expect of them?
What you came across is not a Scrum Team. But that doesn't mean that they are ineffective. Are they delivering what the stakeholders want and need? Are they satisfying your company's expectations?
Don't assume that just because they are not working in the manner you expect that it is wrong. Your description could be a Kanban like process where part of the work in progress is to do the analysis and discovery as the item is pulled into the board. Also, many teams are successfully agile with homegrown processes. The important thing is that they are delivering what is needed when it is needed while they are able to adapt to change easily and quickly.