Why backlog grooming?
- I have always been told, from literature and colleagues that it is important that the product backlog is always up to date, meaning:
It's estimated - at least enough for one sprint.
It's detailed enough
It's got small items on top
The recommendation is to work on the backlog in backlog grooming meetings ideally weekly but at least once per sprint.
My question is: Why is it so important that the backlog is prepared BEFORE the sprint planning meeting? Following the Lean principles it seems to me that it is better to do the slicing and estimation JUST-IN-TIME, meaning jus before or as the first part of the sprint planning meeting, that way:
You know more about the system/product
You have the details fresh in mind when sprint planning begins.
I'm not expecting every member of team to be homogenous but why do you think having "enough" expertise in the fields you describe is unrealistic? I've met more than a couple of guys who can start and finish any story within given expertise areas in reasonable time and quality. Consider those guys working in pairs with others inside a project and in no time that expertise will spread around.
Also we need to consider risks of "not sharing knowledge" besides productivity. Just think about one of our specialists leaving the team, without sharing the knowledge and experience to other team members. How many projects have the luxury to take such a risk?