The Project Aardvark Spec: I can’t tell you how strongly I believe in Big Design Up Front, which the proponents of Extreme Programming consider anathema. I have consistently saved time and made better products by using BDUF and I’m proud to use it, no matter what the XP fanatics claim. They’re just wrong on this point and I can’t be any clearer than that.
You can't be wronger than that, either. Some research could do you well. The functional spec you released would not preclude an agile development system being used. I kept reading, thinking at some point you'd actually back up your claim, but it never came.
Attention Joel (and other haters): Agile does not mean no design.