There’s a good article on Tyner Blain on why you should do iterative development with automated testing, and avoid code freeze ice ages.

From the article:

Steps in a dinosaur’s development process

1. Receive list of requirements/features for the current release.
2. Implement the code for the release.
3. Check the code into source code control.
4. Freeze the code and deliver to the test team.
5. Receive defect reports from test team.
6. Fix all defined defects. Return to step 3 until no bugs are reported.

Steps in a mammal’s development process

1. Receive list of requirements/features for the current release.
2. Implement a subset of the code for the release.
3. Build the solution (using an automated build system)
4. Run the automated test suite. Return to step 2 for this feature and rewrite until no bugs are found.
5. Return to step 2 for each piece of code until all code is complete.

Why the dinosaurs lose

The dinosaurs work without any feedback until they hope they are done. They don’t know if the code is good until the test team reviews it. They know it compiles. That’s not the same thing. Reptilian dinosaurs had tiny little brains, of course they froze. Software dinosaurs don’t have the same excuse.