One of the more important concepts of agile is that there is no one size fits all solution. For this reason I try not to use the term "agile methods" or "process" instead I try to think of the different options available as tools.
In fact, Scrum specifically makes a choice to refer to itself as a framework and not a process. One definition of a framework is "A set of assumptions, concepts, values, and practices that constitutes a way of viewing reality". This is an important distinction, and one I feel many people fail to make. In my mind, agile methods are nothing more then a collection I tools that we can use to get the job done.
With this in mind I think it's important we are always trying to expand our toolkit in order to find the right fit for the situations we are in. I don't know of many successful Scrum implementations that don't use at least some practices from Extreme Programming. Likewise, I often encourage people to take artifacts such as backlogs, and roles such as product owners when using Kanban as a tool in their processes.
So, what I am trying to advocate with this posting is if you are a "Scrum person" take some time to learn about other topics like "the ten commandments of continues improvement". If you are in to Extreme Programming have a look if Kanban practices like work in progress limits might have something to offer you.
"When the only tool you have is a hammer you tend to see every problem as a nail."
So please, add more tools to your toolbox then just a hammer.
Find more tools at Göteborgs next agile conference: