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MURPHY'S LAWS
and Others Reasons Things Go Wrong
Page 3
DESIGNSMANSHIP
If you find errors on these pages... it's to be expected
First Law of Revision:
Information necessitating a change of design will be conveyed to the designer after - and only after - the plans are complete. (often called the "Now they tell us! Law.)
Corollary-
In simple cases, presenting one obvious right way versus one obvious wrong way, it is often wiser to choose the wrong way, so as to expedite subsequent revision.
Second Law of Revision:
The more innocuous the modification appears to be, the further its influence will extend and the more plans will have to be redrawn.
Third Law of Revision:
If, when completion of a design is imminent, field dimensions are finally supplied as they actually are - instead of as they were meant to be - it is always simpler to start all over.
Corollary:
It is usually impractical to worry beforehand about interferences - if you have none, someone will make one for you.
Osborn's Law
Variables won't., constants aren't
Klipstein's Law of Specification:
In specifications, Murphy's Law supersedes ohm's.
Law of the Lost Inch:
In designing any type of construction, no overall dimension can be totaled correctly after 4:40 p.m. on Friday.
Corollaries:
1. Under the same conditions, if any minor dimensions are given to sixteenths of an inch, they cannot be totaled at all.
2. The correct total will become self-evident at 9:01 a.m. on Monday.
Laws of Applied Confusion:
1. The one piece that the plant forgot to ship is the one that supports 75% of the balance of the shipment.
Corollary:
Not only did the plant forget to ship it; 50% of the time they haven't even made it.2. Truck deliveries that normally take one day will take five when you are waiting for the truck.
3. After adding two weeks to the schedule for unexpected delays, add two more for the unexpected, unexpected delays.
4. In any structure, pick out the one piece that should not be mismarked and expect the plant to cross you up
Corollaries,
1. In any group of 6 pieces with the same erection mark on it, one should not have that mark on it.
2. It will not be discovered until you try to put it where the mark says it's supposed to go-
3. Never argue with the fabricating plant about an error. The inspection prints are all checked off, even to the holes that aren't there
Wyszkowski's Theorem:Regardless of the units used by either the supplier or the customer, the manufacturer shall use his own arbitrary units convertible to those of either the supplier or the customer only by means of weird and unnatural conversion factors.
The SNAFU Equations:1. Given any problem containing 'n' equations, there will always be 'n+l' unknowns.
2. An object or bit of information most needed will be the least available.
3. Once you have exhausted all possibilities and fail, there will be one solution, simple and obvious, highly visible to everyone else.
4. Badness comes in waves.
Skinner's ConstantThat quantity which, when multiplied by, divided by, added to, or subtracted from the answer you get, gives you the answer you should have gotten.
(Flannagan's Finagling Factor:)
Miksch's Law:If a string has one end, then it has another end.
As the laws are presented on my weekly e-mail list I will add them here. Come back each week or see them first by sending an e-mail to murphy-subscribe@topica.com
If you have other Murphy type "Laws"to add please E mail me
