Problem:There are two ways people seem to want to use a backlog:
A) To sort by priority, so the next thing we do is the most important thing to do next.
B) To make sure we don't forget anything important.
In both cases, the cost and value get worse as the list grows. Good ideas that are 1/2-way down the list will get duplicated by mistake, but with different phrasing, so the duplication is not obvious. Sorting, de-duping, and understanding the items gets more expensive, but none of that effort actually creates any business value.
I see a lot of teams with backlogs that would take a year to work through, if no new ideas came along. And of course new ideas always come along, at least if you're working on anything that matters.
Since items come in to the backlog faster than they go out, the list steadily grows, and most ideas never leave the backlog. People start to believe that the backlog is where good ideas go to die.
Solution:Keep the backlog short.
7 items seems ideal, because you can keep them all in your head long enough to understand the whole list.
When a new idea appears, compare it to the current backlog, and ask "is this item higher priority than any of the items currently on the list?" If not, then let it go. Don't worry about forgetting. Trust that if it becomes more important, it will grab your attention again, and can be added to the list at that time. More likely, you'll think of something even more awesome, and do that instead. That's a good thing: doing the more awesome things before the less awesome things.
Alternate Solution:In many organizations, my proposal won't fly. People come to the team with requests, and would be upset if you said "It's not in our top 7, so we're letting it go."
In that case, keep two lists. The first list is the stuff you're going to do next (today/this sprint/whatever), and only has a few items on it. The second list is the bucket of possible future ideas, and can be any size. Spend as little time as possible grooming the second list.
When a new idea appears, compare it to the "To Do Next" list, and ask "is this higher priority than any of the items currently on the list?" If not, put it on the "Possible Future Ideas" list. Tell the requester that your idea is "on the backlog," and will be weighed against other items on the backlog when planning future releases. They'll understand that if you didn't do their idea, it's because something even better happened.
Sidebar: Hold prioritization very lightly.We prioritize work by considering the estimated cost and value of that work. Both types of estimates are notoriously unreliable. You may believe you're working on the next most important thing, but you're probably wrong in some way that you can't know yet.
If you start working on an item, stay open to discovering that you should actually be doing something else. As Woody Zuill says:
This is another reason to slice work very thinly. The smaller the item, the sooner you can get to the point where you learn what you should really be doing, and the more likely it is that this current item will get completed and deliver some value before switching to your new discovery.#AgileMaxim 1: It is in the doing of the work that we discover the work that we must do. Doing exposes reality. http://t.co/4WbMeKnqWF— Woody Zuill (@WoodyZuill) July 30, 2015