This post originated from an RSS feed registered with Agile Buzz by Keith Ray. Original Post: Bill on TDD Feed Title: MemoRanda Feed URL: http://homepage.mac.com/1/homepage404ErrorPage.html Feed Description: Keith Ray's notes to be remembered on agile software development, project management, oo programming, and other topics. Latest Agile Buzz Posts Latest Agile Buzz Posts by Keith Ray Latest Posts From MemoRanda

Bill de hÓra wrote good stuff, here's a snippet:

One aspect of TDD is that it persists knowledge about the system, executable knowledge, which was previously transient, unavailable or simply thrown away. Without TTD or test-first, this 50% output/effort was probably never captured. It was spent interpreting print lines and on hours poured over the debugger. Time spent in a debugger is not recyclable, not repeatable, not resuable by others[...].

Without TDD probably less than 20% of your time is in writing code. It's in eyeballing print lines and debugger output, reading an ill-formed spec, being in more and more meetings because things are falling behind, doing everything except adding functionality. Sure, the first month you cranked it and it felt good - we've all been there. But without the continual investment in tests, the ability to keep going and sustain pace falls off - dramatically. [...]