Murphy's Laws of Computer Programming

• Any given program, when running, is obsolete.
• If a program is useless, it will have to be documented.
• If a program is useful, it will have to be changed.
• Any non-trivial program contains at least one bug.
• Any program will expand to fill all available memory.
• The value of a program is directly proportional to the weight of its output.
• The complexity of a program will grow until it exceeds the capability of the programmer to maintain it.
• Make it possible for programmers to write in English and you will find that programmers cannot write in English.
• If builders built buildings the way programmers write programs, the first woodpecker that came along would destroy civilization.
• Inside every small program is a large program struggling to get out.
• If a test installation functions perfectly, all subsequent systems will malfunction.
• Not until a program has been in production for at least six months will its most harmful error be discovered.
• Undetectable errors are infinite in variety, in contrast to detectable errors, which are by definition limited.
• If the input editor has been designed to reject all bad input, an ingenious idiot will discover a method to get bad data past it.
• Build a system that even a fool can use, and only a fool will want to use it.
• Machines work; people should think.
• A carelessly planned project takes three times longer to complete than expected; a carefully planned project will take only twice as long.
• Adding manpower to a late project makes it later.
• The effort required to correct an error increases geometrically with time.
• Only ten percent of the code in any given program will ever be executed.

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