Murphy’s Laws on Design

The first law of correction.

Information leading to unavoidable design changes comes to the developer then, and only when the drawings are ready (often this law is phrased like “We could not say before!”).


In simple cases, when the correct and incorrect ways are clearly visible, it is better to choose the wrong one in order to start changing the design as soon as possible.

Second law of correction.

The more harmless the change seems, the further its influence extends and the more drawings you have to redo.

The third law of correction.

If the product development is near completion and finally the existing parameters are finally provided, they are so different from those that you used in the calculations, that it is easier to start all over again.


Normally, you should not worry about disturbances in advance – if they are not there, someone will create them.

The law is lost in.

When working on any project, no overall size can be set correctly after 4 hours. 40 min. On Friday.


The correct result will be self-evident at 9 o’clock. 01 min. mornings on monday.

The law of applied confusion.

The part that the plant forgot to put, provides 75% of the volume of supplies. Having understood, you will easily find out that the plant not only forgot to put it, but 50% of the time it did not produce at all.


1. Delivery on a truck, usually requiring one day, will take 5 days, if you wait for this particular truck.

2. After adding two weeks to the scheduled time for unforeseen delays, add two more weeks to the unexpectedness of the delays themselves.

Vyshkovsky’s theorem.

Regardless of the units of measurement used by the supplier or the buyer, the manufacturer will use its own units of measure, transferred to the supplier or buyer units using strange and unnatural allocation factors.

Sinefu equations.

1. In the problem of M equations there will always be M + 1 unknown.

2. The most needed subject or the most necessary dose of information will be the least available.

3. As soon as you try all possible solutions and do not find the right one, there will immediately be a simple and obvious solution for all other people.

Brooks Law.

Increasing the number of participants in the preparation of a late program only slows down the process.

Principle of Show.

Create a system that even a fool can use, and only a fool will want to use it.

The Law of the Miksha.

If the rope has one end, then it must have another one.

Law of Hardin.

One can never do one thing.

The law of Hecht.

There is no better time than the present to postpone what one does not want to do.

Grossman’s Lemma.

Any worthwhile work was worth doing yesterday.

Derivative from Murphy’s law proposed by Nagg.

The more complex and grandiose the plan, the more chances that it will fail.

Dehaya axiom.

Simple work is postponed, believing that there will always be time to do it later.

Four principles of the production worker.

1. The set of tools does not have enough of the wrench or drill that is needed.

2. Most operations require three hands.

3. The remaining nuts never fit the remaining bolts.

4. The more carefully drafted, the more confusion, if something went wrong.

Ray’s precision rule.

Measure with a micrometer. Mark with chalk. Cut off with an ax.

The first law of repair.

You can not fix anything that is not broken.

The first rule of smart repair.

Do not throw anything away.

Smith’s computer repair law.

The holes for the screwdriver are always half a millimeter smaller than necessary.


Holes of suitable size will be inaccessible.

The Law of Jaruk.

If the new machine is cheaper, the company will insist on repairing the old one.


If it is cheaper to repair an old machine, the company will insist on buying the latest model.

The laws of engineering design, proposed by Gor.

1. The main function of the developer is to create things that are difficult to produce and impossible to maintain.

2. The component of the circuit, in which the shortest service life, is placed in the least accessible place.

3. Any scheme must contain at least one obsolete detail, two scarce and three at the development stage.


1. The installation engineer will lead the project in accordance with the existing state of the art.

2. These changes will not be mentioned in the operating instructions.

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