David’s laws of specification

I still get a kick out of reading David Bayliss. This is from his 1997 article in Clarion Magazine, Computer Aided Disaster.

1. The specification is always wrong.
2. Insofar as the specification is right it is too vague to be useful.
3. Insofar as the specification is right and specific it almost certainly doesn’t meet the system requirements.
4. Insofar as the specification is right and specific and meets the system requirements when you get the specification it won’t when you finish the application.

The lesson is simple. Producing a program that meets the specification is a flawed, short-termist concept. What we should be attempting to do is produce a program structure that is able to meet the specification (model if you prefer), whatever the specification happens to be.