Murphy's Laws and Other Observations
- If anything can go wrong, it will.
- If there is a possibility of several things going wrong, the one that
will cause the most damage will be the first one to go wrong.
- If anything just cannot go wrong, it will anyway.
- If you perceive that there are four possible ways in which something
can go wrong, and circumvent these, then a fifth way, unprepared for,
will promptly develop.
- Left to themselves, things tend to go from bad to worse.
- If everything seems to be going well, you have obviously overlooked
- Nature always sides with the hidden flaw.
- Mother nature is a bitch.
O'Toole's Commentary on Murphy's Laws
Murphy was an optimist.
- You can't win.
- You can't break even.
- You can't even quit the game.
Forsyth's Second Corollary to Murphy's Laws
Just when you see the light at the end of the tunnel, the roof caves
Nothing is impossible for the man who doesn't have to do it himself.
The Laws of Computer Programming
- Any given program, when running, is obsolete.
- Any given program costs more and takes longer each time it is run.
- If a program is useful, it will have to be changed.
- If a program is useless, it will have to be documented.
- Any given program will expand to fill all the available memory.
- The value of a program is inversely proportional to the weight of
- Program complexity grows until it exceeds the capability of the
programmer who must maintain it.
In any computer system, the machine will always misinterpret,
misconstrue, misprint, or not evaluate any math or subroutines or
fail to print any output on at least the first run through.
Corollary to Pierce's Law
When a compiler accepts a program without error on the first
run, the program will not yield the desired output.
Addition to Murphy's Laws
In nature, nothing is ever right. Therefore, if everything is
going right ... something is wrong.
If at first you don't succeed, transform your data set!
Computing power increases as the square of the cost.
Golub's Laws of Computerdom
- Fuzzy project objectives are used to avoid embarrassment of
estimating the corresponding costs.
- A carelessly planned project takes three times longer to complete
than expected; a carefully planned project takes only twice as
- The effort required to correct course increases geometrically
- Project teams detest weekly progress reporting because it so
vividly manifests their lack of progress.
Variables won't; constants aren't.
Gilb's Laws of Unreliability
- Computers are unreliable, but humans are even more unreliable.
- Any system that depends upon human reliability is unreliable.
- Undetectable errors are infinite in variety, in contrast to
detectable errors, which by definition are limited.
- Investment in reliability will increase until it exceeds the
probable cost of errors, or until someone insists on getting some useful
Lubarsky's Law of Cybernetic Entomology
There's always one more bug.
- Profanity is the one language understood by all programmers.
- Not until a program has been in production for six months will
the most harmful error be discovered.
- Job control cards that positively cannot be arranged in improper
order will be.
- Interchangeable tapes won't.
- 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.
- If a test installation functions perfectly, all subsequent systems
Weinberg's Second Law
If builders built buildings the way programmers wrote programs, then
the first woodpecker that came along would destroy civilization.
The probability of anything happening is in inverse ratio to its
The amount of expertise varies in inverse ratio to the number of
statements understood by the general public.
Zymurgy's First Law of Evolving System Dynamics
Once you open a can of worms, the only way to recan them is to use
a larger can (old worms never die, they just worm their way into
Harvard's Law, as Applied to Computers
Under the most rigorously controlled conditions of pressure,
temperature, volume, humidity and other variables, the computer
will do as it damn well pleases.
It works better if you plug it in.
It won't work.
Horner's Five Thumb Postulate
Experience varies directly with equipment ruined.
Nothing ever gets build on schedule or within budget.
Rule of Accuracy
When working toward the solution of a problem, it always helps if
you know the answer.
Zymurg's Seventh Exception to Murphy's Law
When it rains, it pours.
- Anything that begins well ends badly.
- Anything that begins badly ends worse.
To estimate the time it takes to do a task: estimate the time you
think it should take, multiply by two and change the unit of measure
to the next highest unit. Thus, we allocate two days for a one hour
If it looks easy, it's tough. If it looks tough, it's damn near
No books are lost by lending except those you particularly wanted to
Johnson's Third Law
If you miss one issue of any magazine, it will be the issue that
contains the article, story or installment you were most anxious to read.
Corollary to Johnson's Third Law
All of your friends either missed it, lost it or threw it out.
Harper's Magazine Law
You never find the article until you replace it.
Adding manpower to a late software makes it later.
Finagle's Fourth Law
Once a job is fooled up, anything done to improve it will only make
Whatever you did, that's what you planned.
Any inanimate object, regardless of its position, configuration or
purpose, may be expected to perform at any time in a totally
unexpected manner for reasons that are either entirely obscure or
else completely mysterious.