“A formidable person is one who seems like they’ll get what they want, regardless of whatever obstacles are in the way.” – Paul Graham
A formidable organization is one that limits the creation of internal obstacles.
Editor’s note (2013-08-11):
It occured to me that limiting the creation of internal obstacles is rather good enough. To be truly formidable, an organization would need to actively seek for ways to reduce the number of such obstacles.