When to create a better fire extinguisher

In a work meeting today someone explained an aphorism of the three times to build a better fire extinguisher:

1. Before a fire so you are prepared,
2. After a fire so you are better prepared for the next fire
3. During a fire, which is a terrible idea.

As software developers, we frequently look at all problems and projects as new code (or a cool script) to be written, optimistically predicting we can develop, test, and run the new code and meet the deadline. It's frequently better to use an existing system or process to meet a tight, important deadline than to bet your reputation that your new code will work perfectly the first time.