Lean and Agile complement each other.
If time-boxed fixed scope scrums are not the easy for the task focused team, Kanban can help in process and task visualization, reducing WIP, process improvements, focused efforts, reducing the waste, reducing the delivery time, realizing the value stream and generating continuous flow in development.
What is Kanban and how it can be applied to software development functions? –
Good article from Kenji Hiranabe in http://www.infoQ.com