Laws of Software Development

by Joey deVilla

Inspired by Phil Haack's article 19 Eponymous Laws of Software Development, I decided to collect laws, axioms and rules pertaining to mainstream software development. This is by no means a complete list of laws; I've purposely stuck to the ones that apply to everyday software development and steered clear of the more theoretical ones. Maybe I'll compile a more complete list someday. You'll notice that some of the laws come from the world of biology - they also appear in some lists of software laws, and I think they still apply.

The Law

Who Said It

What it Says

Amdahl's Law

Gene Amdahl

The speedup gained from running a program on a parallel computer is greatly limited by the fraction of that program that can't be parallelized.

Augustine's Second Law of Socioscience

Norman Augustine

For every scientific (or engineering) action, there is an equal and opposite social reaction.

Brooks' Law

Fred Brooks

Adding manpower to a late software project makes it later.

Clarke's First Law

Arthur C. Clarke

When a distinguished but elderly scientist states that something is possible he is almost certainly right. When he states that something is impossible, he is very probably wrong.

Clarke's Second Law

Arthur C. Clarke

The only way of discovering the limits of the possible is to venture a little way past them into the impossible.

Clarke's Third Law

Arthur C. Clarke

Any sufficiently advanced technology is indistinguishable from magic.

Conway's Law

Melvin Conway

Any piece of software reflects the organizational structure that produced it.

Cope's Rule

Edward Drinker Cope

There is a general tendency toward size increase in evolution.

Dilbert Principle

Scott Adams

The most ineffective workers are systematically moved to the place where they can do the least damage: management.

Ellison's Law of Cryptography and Usability

Carl Ellison

The userbase for strong cryptography declines by half with every additional keystroke or mouseclick required to make it work.

Ellison's Law of Data

Larry Ellison

Once the business data have been centralized and integrated, the value of the database is greater than the sum of the preexisting parts.

The Law of False Alerts

George Spafford

As the rate of erroneous alerts increases, operator reliance, or belief, in subsequent warnings decreases.

Fisher's Fundamental Theorem

R. A. Fisher

The more highly adapted an organism becomes, the less adaptable it is to any new change.

Fitts' Law

Paul Fitts

The time to acquire a target is a function of the distance to and the size of the target.

Flon's Axiom

Lawrence Flon

There does not now, nor will there ever, exist a programming language in which it is the least bit hard to write bad programs.

Gilder's Law

George Gilder

Bandwidth grows at least three times faster than computer power.

Godwin's Law

Mike Godwin

As an online discussion grows longer, the probability of a comparison involving Nazis or Hitler approaches one.

Grosch's Law

Herb Grosch

The cost of computing systems increases as the square root of the computational power of the systems.

Hartree's Law

Douglas Hartree

Whatever the state of a project, the time a project-leader will estimate for completition is constant.

Heisenbug Uncertainty Principle

Jim Gray

Most production software bugs are soft: they go away when you look at them.

Hick's Law

William Edmund Hick

The time to make a decision is a function of the possible choices he or she has.

Hoare's Law of Large Programs

C. A. R. Hoare

Inside every large problem is a small problem struggling to get out.

Hofstadter's Law

Douglas Hofstadter

A task always takes longer than you expect, even when you take into account Hofstadter's Law.

Jakob's Law of the Internet User Experience

Jakob Nielsen

Users spend most of their time on other sites. This means that users prefer your site to work the same way as all the other sites they already know.

Joy's Law

Bill Joy

smart(employees) = log(employees), or "No matter who you are, most of the smartest people work for someone else."

Kerckhoffs' Principle

Auguste Kerckhoffs

In cryptography, a system should be secure even if everything about the system, except for a small piece of information - the key - is public knowledge.

Linus' Law

Eric S. Raymond, who named it after Linus Torvalds

Given enough eyeballs, all bugs are shallow.