Murphy's law

1. If anything can go
If anything can go
wrong, it will
wrong, it will
Murphy’s
Law
Murphy’s Law
Murphy’s Law
If there is a possibility
If there is a possibility If nothing can just go
If nothing can just go
of several things going
of several things going wrong, it will anyway
wrong, it will anyway
wrong, the one that will
wrong, the one that will
cause the most damage
cause the most damage
will be the first one to
will be the first one to
go wrong
go wrong
Murphy’s Law
Murphy’s Law Murphy’s Law
Murphy’s Law
Page 1 Murphy’s Law
If there are 4 possible
If there are 4 possible Left to themselves,
Left to themselves,
ways in which something
ways in which something things tend to go from
things tend to go from
can go wrong, and you
can go wrong, and you bad to worse
bad to worse
circumvent these, then a
circumvent these, then a
5th way, unprepared
5th way, unprepared
for, will immediately
for, will immediately
occur
occur
Murphy’s Law
Murphy’s Law Murphy’s Law
Murphy’s Law

2. If things seem to be
If things seem to be Nature always sides
Nature always sides
going well, you have
going well, you have with the hidden flaw
with the hidden flaw
obviously overlooked
obviously overlooked
something
something
Murphy’s Law
Murphy’s Law Murphy’s Law
Murphy’s Law
O'Toole's Commentary
O'Toole's Commentary Ginsberg's Theorems
Ginsberg's Theorems
on Murphy's Laws -
on Murphy's Laws - •you can't win
•you can't win
Murphy was an
Murphy was an •you can't break even
•you can't break even
optimist
optimist •you can't even
•you can't even
quit the game
quit the game
Murphy’s Law
Murphy’s Law Murphy’s Law
Murphy’s Law
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Forsyth's Second Corollary
Forsyth's Second Corollary Weiler's Law - nothing
Weiler's Law - nothing
to Murphy's Law - just
to Murphy's Law - just is impossible for the
is impossible for the
when
when person who doesn't have
person who doesn't have
you can see the light at
you can see the light at
to do it themself
to do it themself
the end of the tunnel, the
the end of the tunnel, the
roof caves in.
roof caves in.
Murphy’s Law
Murphy’s Law Murphy’s Law
Murphy’s Law

3. The Laws of Computer
The Laws of Computer Any given program costs
Any given program costs
Programming - any given
Programming - any given more and takes longer
more and takes longer
program, when running,
program, when running, each time it is run
each time it is run
is obsolete
is obsolete
Murphy’s Law
Murphy’s Law Murphy’s Law
Murphy’s Law
If a program is useful,
If a program is useful, If a program is useless,
If a program is useless,
it will have to be
it will have to be it will have to be
it will have to be
replaced
replaced upgraded
upgraded
Murphy’s Law
Murphy’s Law Murphy’s Law
Murphy’s Law
Page 3 Murphy’s Law
Any given program will
Any given program will The value of a program
The value of a program
expand to over-fill the
expand to over-fill the is inversely proportional
is inversely proportional
available memory
available memory to the amount it costs
to the amount it costs
Murphy’s Law
Murphy’s Law Murphy’s Law
Murphy’s Law

4. Program complexity
Program complexity Addition to Murphy's
Addition to Murphy's
grows until it exceeds
grows until it exceeds Law - in nature, nothing
Law - in nature, nothing
the capability of the
the capability of the is ever right, therefore,
is ever right, therefore,
programmer who must
programmer who must if everything is going
if everything is going
maintain it
maintain it
right... something is
right... something is
wrong
wrong
Murphy’s Law
Murphy’s Law Murphy’s Law
Murphy’s Law
Brook's Law - if at
Brook's Law - if at Grosch's Law costs
Grosch's Law costs
first you don't succeed,
first you don't succeed, increase as the square
increase as the square
hire a consultant
hire a consultant of the computing power
of the computing power
Murphy’s Law
Murphy’s Law Murphy’s Law
Murphy’s Law
Golub's Laws of
Golub's Laws 4
Page of
A Murphy’s Law planned
A carelessly planned
carelessly
Computerdumb - fuzzy
Computerdumb - fuzzy project takes 3 times
project takes 3 times
project objectives are
project objectives are
longer to complete than
longer to complete than
used to avoid the
used to avoid the
embarrassment of expected; a carefully
expected; a carefully
embarrassment of
estimating the
estimating the planned project takes
planned project takes
corresponding costs
corresponding costs five times as long
five times as long
Murphy’s Law
Murphy’s Law Murphy’s Law
Murphy’s Law

5. Osborn's Law: variables
Osborn's Law: variables To err is human,
won't; constraints aren't
won't; constraints aren't but to really
screw up you
need a computer
Murphy’s Law
Murphy’s Law Murphy’s Law
Murphy’s Law
Any system that
Any system that Gubarsky's Law of
Gubarsky's Law of
depends on human
depends on human Cybernetic Entomology:
Cybernetic Entomology:
reliability is unreliable
reliability is unreliable there's always at least
there's always at least
one more bug
one more bug
Murphy’s Law
Murphy’s Law Murphy’s Law
Murphy’s Law
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Groutman's Postulate:
Groutman's Postulate: It won’t be until a
It won’t be until a
profanity is the one
profanity is the one program has been in
program has been in
language understood by
language understood by production for 6
production for 6
months the the most
months the the most
all programmers
all programmers
harmful error will be
harmful error will be
discovered
discovered
Murphy’s Law
Murphy’s Law Murphy’s Law
Murphy’s Law

6. Cables & card that
Cables & card that Switchable cables won't.
Switchable cables won't.
absolutely can’t be
absolutely can’t be
connected in the wrong
connected in the wrong
way will be
way will be
Murphy’s Law
Murphy’s Law Murphy’s Law
Murphy’s Law
Weinberg's Second Law of
Weinberg's Second Law of Sumperson's Law: the
Sumperson's Law: the
Relativity: if builders built
Relativity: if builders built probability of anything
probability of anything
buildings the way
buildings the way happening is in inverse
happening is in inverse
programmers wrote
programmers wrote
ratio to its desirability
ratio to its desirability
programs, then the first
programs, then the first
or need
or need
woodpecker that came along
woodpecker that came along
would destroy civilization
would destroy civilization
Murphy’s Law
Murphy’s Law Murphy’s Law
Murphy’s Law
Page 6 Symurgy's Law Law of
Symurgy's 1st Law of
Murphy’s 1st
Gummidge's Law: the
Gummidge's Law: the
Evolving System Dynamics:
Evolving System Dynamics:
amount of expertise
amount of expertise once you open a can of
once you open a can of
varies in inverse
varies in inverse worms, the only way to
worms, the only way to
proportion to the number
proportion to the number recan them is to use a
recan them is to use a
of
of larger can- old worms
larger can- old worms
statements understood never die, they just worm
never die, they just worm
statements understood
their way into larger cans
their way into larger cans
by the general public Law
by the general public Law
Murphy’s
Murphy’s Murphy’s Law
Murphy’s Law

7. Harvard's Law, as applied
Harvard's Law, as applied
Battinger's Law: it
Battinger's Law: it
to computers: under the
to computers: under the
most rigorously controlled
most rigorously controlled
works better if you plug
works better if you plug
conditions of pressure,
conditions of pressure, it in
it in
temperature, volume,
temperature, volume,
humidity, and other
humidity, and other
variables, the computer will
variables, the computer will
do as it damn well pleases
do as it damn well pleases
Murphy’s Law
Murphy’s Law Murphy’s Law
Murphy’s Law
Henkinson's Law: But
Henkinson's Law: But Koerner's Five Thumb
Koerner's Five Thumb
even then it won't work
even then it won't work Postulate: experience
Postulate: experience
varies directly with
varies directly with
equipment ruined
equipment ruined
Murphy’s Law
Murphy’s Law Murphy’s Law
Murphy’s Law
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Cheop's Law: nothing
Cheop's Law: nothing Beaumont's Rule of
Beaumont's Rule of
ever gets built on
ever gets built on Accuracy: when working
Accuracy: when working
time or within budget
time or within budget toward the solution of a
toward the solution of a
problem, it always helps
problem, it always helps
if you know the answer
if you know the answer
Murphy’s Law
Murphy’s Law Murphy’s Law
Murphy’s Law

8. Wymurg's 7th Exception
Wymurg's 7th Exception Fudder's Laws:
Fudder's Laws:
to Murphy's Law: when
to Murphy's Law: when anything that begin
anything that begin
it rains it floods
it rains it floods well ends badly,
well ends badly,
anything that begins
anything that begins
badly ends worse
badly ends worse
Murphy’s Law
Murphy’s Law Murphy’s Law
Murphy’s Law
Westheimer's Rule: to estimate
Westheimer's Rule: to estimate
the time it takes to do a task,
the time it takes to do a task, Stockmayer's
Stockmayer's
estimate the time you think it
estimate the time you think it
Theorem:
Theorem:
should take, multiply by 2 and
should take, multiply by 2 and
change the unit of measure to
change the unit of measure to if it looks easy, it's
if it looks easy, it's
the next highest unit. Thus we
the next highest unit. Thus we tough. If it looks
tough. If it looks
allocate 2 days for a 1 hour task
allocate 2 days for a 1 hour task
tough, it's damn near
tough, it's damn near
impossible
impossible
Murphy’s Law
Murphy’s Law Murphy’s Law
Murphy’s Law
Page 8 Johnson's Law
Johnson's Third Law: If
Murphy’s Third Law: If
Atwood's Corollary: No
Atwood's Corollary: No you miss one issue of any
you miss one issue of any
books are lost by
books are lost by magazine, it will be the
magazine, it will be the
lending except those
lending except those issue that contains the
issue that contains the
you particularly needed
you particularly needed article, story, information,
article, story, information,
or installment that you
or installment that you
to keep
to keep
were most anxious to read
were most anxious to read
Murphy’s Law
Murphy’s Law Murphy’s Law
Murphy’s Law

9. Corollary of Johnson's
Corollary of Johnson's Harper's Magazine
Harper's Magazine
Third Law: All of your
Third Law: All of your Law: You never find
Law: You never find
friends either missed
friends either missed the article until you
the article until you
it, lost it or threw it
it, lost it or threw it replace the equipment
replace the equipment
out
out
Murphy’s Law
Murphy’s Law Murphy’s Law
Murphy’s Law
Brooke's Law: Adding
Brooke's Law: Adding Nagle's Fourth Law:
Nagle's Fourth Law:
manpower to a late
manpower to a late Once a job is fouled
Once a job is fouled
project makes it
project makes it up, anything done to
up, anything done to
even later
even later improve it will only
improve it will only
make it worse
make it worse
Murphy’s Law
Murphy’s Law Murphy’s Law
Murphy’s Law
Flap's Law: Any inanimate
Flap's Law: Any inanimate
Page 9 Murphy’s Law
Heatherkile's Rule: object, regardless of its
object, regardless of its
Heatherkile's Rule:
position, configuration, or
position, configuration, or
Whatever you did,
Whatever you did, purpose, may be expected to
purpose, may be expected to
that's what you planned
that's what you planned perform at any time in a
perform at any time in a
totally unexpected manner for
totally unexpected manner for
reasons that are either
reasons that are either
entirely obscure or else
entirely obscure or else
completely mysterious.
completely mysterious.
Murphy’s Law
Murphy’s Law Murphy’s Law
Murphy’s Law

10. Jukes' Axiom: The
Jukes' Axiom: The
number of potholes in
number of potholes in Collins' Law: If you can't
Collins' Law: If you can't
the road or speed make a mistake, you
make a mistake, you
the road or speed
bumps in the parking lot can't make anything.
can't make anything.
bumps in the parking lot
proportionally increases
proportionally increases
in relation to the
in relation to the
amount of data stored
amount of data stored
on the hard drive Murphy’s Law
in
on the hard drive Murphy’s Law
in Murphy’s Law
Murphy’s Law
If I'm being stupid, that's
If I'm being stupid, that's
Rabinovitch's Rules of
Rabinovitch's Rules of my problem.
my problem.
Sane Dialogue: Everyone
Sane Dialogue: Everyone
If my being stupid makes
If my being stupid makes
who matters is stupid
who matters is stupid you stupid, that's your
you stupid, that's your
now and then
now and then problem.
problem.
If you think you're never
If you think you're never
Murphy’s Law
Murphy’s Law stupid, boy are you stupid! Law
stupid, boy are you stupid! Law
Murphy’s
Murphy’s
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