So you only test those cases you have thought can fail(which is compulsory to test anyway). The purpose of the Monkey Chaos is to trigger situations you haven't

So you only test those cases you have thought can fail(which is compulsory to test anyway). The purpose of the Monkey Chaos is to trigger situations you haven't dreamed about. OK, it ain't perfect. Things usually doesn't fail in a uniformaly distributed way and you can't be sure you'll see a different kind of fail on production, but it sounds useful(yeah, and pretty cool) nonetheless.