Comparing software development to bridge or building construction is a completely bogus straw man. Software and other engineering or building disciplines are too different for any but the most superficial comparisons to be meaningful. (Sure, they all have a creative element, but that's like saying that software development is the same as interpretive dance.) The same applies to comparisons with manufacturing. When you build a bridge, you build exactly what's specified and do not deviate. You apply mathematics to determine if the bridge won't collapse, and you can't argue with the math. Estimates work because you've built many bridges in the past and know exactly what's required in terms of both materials and labor. That's not the way software development works. When we try to build software the same way we build bridges or houses, we fail. It's like claiming that the rules of baseball apply to competitive swimming. Sure, they're both sports, but…