In case you are interested in Shape Up and want read more about it, Ryan Singer - the inventor of the methodology - has written a really great book about how they have been, and currently are, building and shipping products and features at 37signals.

The book is called "Shape Up" (doh) and the electronic version is totally free:

https://basecamp.com/shapeup

I would also really recommend the rest of the books, lots of great thoughts on development and management from actual experience. Also free:

https://37signals.com/books