David Joyce and Dr Peter Middleton have studied the application of (what I call) Lean-Kanban in BBC.
From the abstract:
The evidence shows that over the 12-month period, lead time to deliver software improved by 37%, consistency of delivery rose by 47%, and defects reported by customers fell 24%.
The significance of this work is showing that the use of lean methods including visual management, team-based problem solving, smaller batch sizes, and statistical process control can improve software development.
….The faster delivery with a focus on creating the highest value to the customer also reduced both technical and market risks.
There’s more info on David’s blog, and you can also read the case study itself prior to publication from there.
Update: The case study was published in 2012.