Serial entrepreneur Steve Blank has an excellent post on his blog about the value of business models vs. business plans.
He points out the ultimate benefit of making a dynamic business model: being able test your assumptions before you waste time crafting a plan that might not actually work.
Blank compares two early-stage startups: one that had spent the last 3 months researching and writing up their business plan -- while the other spent their 3 months building and testing their business model.
This link was found on Innovation Daily.