

We will deliver defect free software every time - is this motto workable? - setandbma
http://setandbma.wordpress.com/2012/09/11/agile-and-defect/

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lutusp
> We will deliver defect free software every time - is this motto workable?

No, it isn't. It isn't because the Turing halting problem is known to be
undecidable. This doesn't mean defect free software cannot be written, it
means this cannot be proven.

<http://en.wikipedia.org/wiki/Halting_problem>

A quote: "Alan Turing proved in 1936 that a general algorithm to solve the
halting problem for all possible program-input pairs cannot exist. A key part
of the proof was a mathematical definition of a computer and program, what
became known as a Turing machine; the halting problem is undecidable over
Turing machines."

In layman's terms, this means a company promising defect-free software is just
asking for trouble. It is to software development what an "unsinkable" ocean
liner like the Titanic is to world travel.

> These questions are not rhetorical.

On the contrary, to anyone familiar with the basic principles of computer
science, the question is rhetorical and the answer is "no".

