Requirements Proverbs

Requirements & Design

The proof of the pudding is in the eating.
Traditional English Proverb.

By their fruits ye shall know them.
St. Matthew, VII, 16

Users don't know what they want
until you show it to them.
An old Programmer's Proverb,
according to Kent Beck.

Requirements are the What.
Design is the How.
A System Engineer's Saying.

We aren't ultimately interested in correct models
but in correctly running systems.
Markus Völter

A doctor can bury his mistakes
but an architect can only advise his client to plant vines.
Frank Lloyd Wright, Architect (1867-1959)

Writing system software is like planning a family.
If you make a mistake you have to live with it for 20 years.
Richard Marshall, Software Engineer

Requirements

One year's seeding is seven years' weeding.

A stitch in time saves nine.

Look before you leap.

Experience is a hard schoolmaster -
but fools will learn from no other.

Necessity is the mother of invention.

Where there's a will, there's a way. 
Traditional English Proverbs

Ask for what you want. 
Urban Wisdom

Ask and it shall be given unto you. 
St. Matthew, VII, 7

The cobbler's children go unshod.
which of course means:
Requirements Engineers never write down their own requirements. 
Traditional English Proverb

The difference between the almost right word
and the right word is really a large matter.
Mark Twain, Author (1835-1910)

A quoi ça sert?
What's it for?
President Chirac (of France)
on being shown the Millennium Dome
- which has no discernible function -
by Prime Minister Blair

Those who cannot remember the past
are condemned to repeat it.
or:
Those who have never heard of good system development practice
are condemned to reinvent it.
George Santayana
Life of Reason, Reason in Common Sense, chapter 12, 1905-6

This has been misquoted so often that it is tempting to rephrase it:
Those who cannot remember a quotation are condemned to, er, misquote it. 


Martin Feather's version of Santayana is:
Those who remember the past are doomed to a sense of deja vu.
i.e.
if you wait long enough, engineering fashion will come round again.
Martin's T-shirt shows one of M. C. Escher's Birds paintings,
and he and the birds appear recursively in not-quite-infinite regress in the monitor image.
Shades of Douglas Hofstadter. 

There is no fair wind for one who knows not whither he is bound. 
Lucius Annæus Seneca (the Younger), philosopher, 3-65 AD
quoted by Hull, Jackson, & Dick

If you don't know where you're going, you're unlikely to end up there.
Forrest Gump

Would you tell me please, which way I ought to go from here?
That depends a good deal on where you want to get to, said the cat.
I don't much care where -, said Alice.
Then it doesn't matter which way you go, said the cat. 
Lewis Carroll,
Alice in Wonderland, Chapter 6.
quoted by Tom Gilb, Competitive Engineering
(The fine illustration is by Sir John Tenniel)

Intellectuals solve problems,
geniuses prevent them.
Albert Einstein (1879-1955)

The academic system of measuring performance
leads to the creation of large numbers of write-only publications.
Ian Sommerville

A large chunk of the Computer Science community do not think that it is an engineering discipline,
and hence do not understand what's involved in working on real problems.
Ian Sommerville

Fare buon vino è semplice ma non facile.
Writing good requirements is simple but not easy.
(for a literal translation, try Google)
An Italian peasant farmer,
quoted by Richard Stevens

Training & Consultancy

We have learned nothing.
Pablo Picasso
on emerging from the Lascaux caves
(full of 40,000-year old Modern Art).

Consultancy can be too short;
or too long.
Gerald M Weinberg

The role of a trainer or consultant is to empower the customer,
not to make himself indispensable.
Bertrand Meyer

Ada gula, ada semut.
Where there is sugar, there are ants. 
Malay Proverb

Few people request influence when their world is behaving rationally.
As a result, consultants tend to see more than their fair share of irrationality. 
Gerald M. Weinberg,
The Secrets of Consulting

It is a remarkable observation that
the more learned and respected the researcher,
the simpler their talks often seem to be. 
Mike Grimble

To be good is noble,
but to teach others how to be good is nobler – and less trouble.
Mark Twain, Author (1835-1910)

Discovery

Requirements cannot be observed or asked for from the users,
but have to be created together with all the stakeholders. 
Vesa Torvinen, University of Turku

You can observe a lot by watching.
Yogi Berra

Nature has given us 2 ears but only 1 mouth.
Listen and speak in that ratio.
Benjamin Disraeli (1804 - 1881),
quoting Stoic philosopher Epictetus (AD 55 - c135)

The sound of anything coming at you
– a train, say, or the future – has a higher pitch
than the sound of the same thing going away. 
What Engineers Know, and How They Know It
Walter Vincenti, 1990
Angle of Repose,
Wallace Stegner, 1971

Geologists take NOTHING for Granite
seen on a geology student's T-shirt

Hard Cases make Bad Law. 
The Lawyer's Maxim
(presumably about Case-Based Rule Induction)

Between thought and expression
lies a lifetime
 Lou Reed, Some Kinda Love,
The Velvet Underground, 1969

I keep six honest serving-men
  (They taught me all I knew)
Their names are What and Why and When
  And How and Where and Who.
Rudyard Kipling
Just So Stories, Macmillan, London 1902
mentioned by Ellen Gottesdiener

Father Brown laid down his cigar and said carefully:
It isn't that they can't see the solution.
It is that they can't see the problem. 
G. K. Chesterton
The Point of a Pin
in The Father Brown Stories.
Cassell & Co, London 1929

I owe my success to having listened respectfully to the very best advice,
and then going away and doing the exact opposite.
G. K. Chesterton

When "everyone knows" that something is so,
it is always more interesting and often illuminating to assume
exactly the opposite, and to see where that leads.
G. K. Chesterton

"I am only looking for one word," said Father Brown. "A word that isn't there."
"Well," asked Flambeau; "are you going to tell me anything about it?"
"I must divide it into two parts," remarked the priest.
"First there is what everybody knows; and then there is what I know.
Now, what everybody knows is short and plain enough. It is also entirely wrong."
The Sign of the Broken Sword
in The Father Brown Stories.
G. K. Chesterton

Is ditchwater dull? Naturalists with microscopes
have told me that it teems with quiet fun.
G. K. Chesterton

There is no such thing on earth as an uninteresting subject;
the only thing that can exist is an uninterested person.
G. K. Chesterton

Is'al mujarrib wala tas'al Tabib.
Ask an experienced user rather than an 'Expert'.
A little more precisely:
If you want to know what it feels like, ask a patient, not a doctor. 
Arabic Proverb

Delivery is not necessarily the best time to discover the user requirements. 
Alexander's 17th Law of Requirements

Negotiation builds a team as well as a set of requirements. 
Barry Boehm

Participation is the very expression of permanent discomfort. 
John Ralston Saul
The Unconscious Civilization

Where ignorance is bliss
'tis folly to be wise. 
Thomas Gray (1742)
speaking about the advantages of not claiming
domain expertise when eliciting requirements,
according to Daniel Berry

Review, Validation, Quality

"Most rock journalism is people who can't write,
interviewing people who can't talk,
for people who can't read."
Frank Zappa

I have a method when reviewing books
that involves making a pencilled note on the flyleaf
whenever the author makes an interesting point.
Just a page number and a short memory-jogging quote.
Nicholas Lezard

Final Review is not necessarily the best time to discover the user requirements. 
Alexander's 18th Law

Goals

We'll just list high-level goals
and give the contractors maximum flexibility for how to meet those goals.
Phil McAlister of NASA,
on the new way to procure satellite launchers.
(Yes, this is rocket science.)

Perfection of means,
and confusion of goals
seem, in my opinion, to characterize our age. 
Albert Einstein, 1940/41
cited by Tom Gilb

Goals are dreams with deadlines
Diana Scharf-Hunt

People don't want to buy a quarter-inch drill.
They want a quarter-inch hole!
Theodore Levitt (1925-2006)
Harvard Professor of Marketing

An industry begins with the customer and his or her needs,
not with a patent, a raw material, or a selling skill
Theodore Levitt

The deterministic approach
of deriving requirements from needs
(and systems from requirements)
does not adequately address
the socially constructed usefulness and usability of systems.
Joshua B Gross

La perfection est atteinte non quand il ne reste rien à ajouter,
mais quand il ne reste rien à enlever.
Perfection is reached
not when there's nothing to add,
but when there's nothing to take away.  
Antoine de Saint-Exupéry [1900-1944], pilot and author
quoted by Alistair Cockburn

The real art is knowing what to leave out,
not what to put in.
Steve Jobs' version of Saint-Exupéry's maxim.

All projects are iterative -
it's just that some managers
choose to have the iterations
after delivery. 
Urban Wisdom

Plan to throw one away -
you will, anyhow. 
Frederick Brooks
The Mythical Man-Month

Exceptions

What's your biggest problem?
Events, dear boy, Events. 
Harold 'Supermac' Macmillan (1894-1986)
(supposedly)

Life is one darn thing after another. 
Calvin Coolidge (1872-1933)
(a former US President)

There's many a slip
'twixt cup and lip.

An ounce of prevention 
is worth a pound of cure. 

Traditional English Proverbs

If anything can go wrong, it will, 
and at the worst possible time. 
Popular Version of Murphy's Law

If there is any way for that man to do the job wrong, 
he'll do it that way. 
The real Captain Edward Murphy, USAAF
Edwards Air Force Base, 1949

The unfortunate man referred to by Capt. Murphy was a technician
who installed some instrumentation incorrectly for a rocket-sled test.

The exception proves the rule.
where 'proves' means 'tests' rather than 'confirms',
i.e. the rule is tested by examining its boundary.  
Traditional English Proverb,
with gloss by Michael Jackson.

The Warrior [armoured vehicle] is quite tough.
Apart from the one petrol bomb that went into the turret, 
nothing was seriously wrong. 
L/Cpl Jo McCann,
describing a much-filmed incident that both crew and vehicle survived.

Formal Methods, Semantics, Precision, Proof

Beware of bugs in the above code;
I have only proved it correct, not tried it.
Donald Knuth
Notes on the van Emde Boas construction of priority deques: An instructive use of recursion

Science is what we understand well enough to explain to a computer.
Art is everything else we do.
 Donald Knuth

Premature optimization is the root of all evil (or at least most of it) in programming.
Donald Knuth

There is an inherent dissonance
between the quasi-formal world of computer programs
- defining the programmed machine in each system -
and the non-formal problem world of the system requirements.
Michael Jackson, Foreword to Axel van Lamsweerde's Requirements Engineering

In theory there is no difference between theory and practice.
In practice there is.
Yogi Berra

Nothing can be more fatal to progress 
than a too confident reliance on mathematical symbols; 
for the student is only too apt to take the easier course, 
and consider the formula not the fact as the physical reality. 
Lord Kelvin

The art of fortifying
does not consist in applying rules or following a procedure,
but in good sense and experience. 
Maréchal Sébastien le Prestre de Vauban
(1633-1707, Military Engineer to King Louis XIV)

So-called “natural language” is wonderful for the purposes it was created for,
such as to be rude in, to tell jokes in, to cheat or to make love in
(and Theorists of Literary Criticism can even be content-free in it),
but it is hopelessly inadequate when we have to deal unambiguously
with situations of great intricacy, situations which unavoidably arise
in such activities as legislation, arbitration, mathematics or programming.” 
E. W. Dijkstra's foreword to
Teaching and Learning Formal Methods,
eds. C. N. Dean & M. G. Hinchey, Academic Press, 1996

To a person who only has a hammer,
every problem looks rather like a nail. 
Traditional English Proverb, 
quoted by Michael Jackson.

Requirements in mathematical language are no use
unless they are easier to read than the code. 
David Parnas

There's no point in being exact about something
if you don't even know what you're talking about. 
John von Neumann

There is simply no substitute for knowing what you're doing. 
Jeff Case (coinventor of SNMP)

|
No methodology will ever replace bright, dedicated people. 
Brad Parkinson (the father of GPS)

A formal representation should be as simple as possible,
but no simpler. 
Pamela Zave & Michael Jackson,
4 Dark Corners of RE, 1996, ACM

RE is at the borderline between the informal and the formal. 
Prof. Dr. Manfred Broy,
Tech. Univ. München

JSP and JSD were less universal in their application than we had at first supposed.
This was not a defect.
It was an important technical strength:
effective software development methods must be sharply focused
to exploit the characteristics of particular classes of problem and system. 
Michael Jackson:
The Origins of JSP and JSD: a Personal Recollection,
IEEE Annals of Software Engineering
Vol 22 No 2, 61-63, Apr-Jun 2000

Light & Agile Methods
(See also: Iteration)

Two weeks later, the customer gave feedback on the implementation,
the espresso and muffins arrived,
and the next two-week cycle began.
I suspect this approach works mainly because everyone prefers
muffins and espresso to writing specifications.
Ian Gorton

A complex system that works is invariably found
to have evolved from a simple system that worked.

A complex system designed from scratch never works
and cannot be patched up to make it work.
Gall's Law
John Gall, Systemantics: How systems really work and how they fail, 1986

Do the simplest thing that could possibly work.
Kent Beck

Nothing in Excess. 
Inscription over the entrance to the Oracle at Delphi,
prophesying the coming of Agile Methods. Possibly.

Slow is good. 
The Ada programmer's proverb.

Patience is a virtue.

More haste, less speed. 
Traditional English Proverbs.

Faire de la bonne cuisine demande un certain temps.
Si on vous fait attendre, c'est pour mieux vous servir, et vous plaire.
Good cooking takes time.
If you are made to wait, it is to serve you better, and to please you.
Menu of Restaurant Antoine, New Orleans
Chapter 2 of The Mythical Man-Month (Fred Brooks), 1975

Planning Proverbs

The plan is nothing;
the planning is everything. 
Dwight Eisenhower
(according to Jerry Weinberg)

Plans are only good intentions
unless they immediately degenerate into hard work. 
Peter Drucker, Pioneering management guru (1909-2005)

The bearing of a child takes nine months,
no matter how many women are assigned.
Fred Brooks,
The Mythical Man-Month, 1975, chapter 2

Management Maxims

Change always follows the same pattern.
If you come up with something new they try and put you off.
If that doesn't work they call you stark raving bonkers.
If that doesn't work they lock you up like the suffragettes.
Then, after a pause, the change happens
and you can't find anyone that doesn't claim to have been fighting for it with you.
Tony Benn (politician)

I love deadlines.
I love the whooshy sound they make as they go by.
Douglas Adams (author, 1952-2001)

You can have it good, fast, or cheap:
pick any two.
The Project Manager's Maxim

The first 90% of the software code takes 90% of the development time.
The remaining 10% of the code takes up the other 90% of the time.
Cargill's Law
Tom Cargill, Bell Labs

Estimated time to completion of the project is constant.
or
The project is 90% complete,
and will be ready in 6 months.
(adjust the figures to taste)
"Hartree's Law"
The attribution to Douglas Hartree (mathematician, 1897-1958) is obscure.
 Perhaps somebody confused Hartree with Cargill?

Adding manpower to a late software project makes it later.
Brooks' Law
Fred Brooks
The Mythical Man-Month, 1975, chapter 2

Management is doing things right;
leadership is doing the right things.
Peter Drucker

There is nothing so useless
as doing efficiently
that which should not be done at all.
Peter Drucker

Teaching 23-year-olds in an MBA programme
strikes me as largely a waste of time.
They lack the background of experience.
You can teach them skills - accounting and what have you -
but you can't teach them management. 
Peter Drucker (1909-2005)
'The world's first management guru'

A factor present in every successful project
and absent in every unsuccessful project
is sufficient attention to requirements. 
Suzanne & James Robertson
Requirements-Led Project Management

Audacem fortuna iuvat.
Lyckan står dem djärvom bi.
Fortune favours the bold.  
Latin, Swedish & English proverbs.

Reinforce Success.
  I have seen this seriously misquoted as
'Reinforce Strength'.
That isn't the same thing at all!
Who'd want to be even stronger on some Maginot Line,
where mobility and freedom of action are sacrificed?  
The General's Maxim

We'll cross that bridge ... when it falls down. 
The Team Leader's Maxim

When frying small fish, disturb them little. 
Confucius (attrib.)

Nothing can change without a management commitment. 
Ivy Hooks
Customer-Centered Products, 2001

Estimation and Sizing Sayings

Hofstadter's Law
It always takes longer than you expect,
even when you take Hofstadter's Law into account.
Douglas Hofstadter
(in a typically recursive statement)
Escher, Gödel, Bach, an Eternal Golden Braid, 1979

For which of you, intending to build a tower, sitteth not down first,
and counteth the cost, whether he have sufficient to finish it?
Lest haply, after he hath laid the foundation, and is not able to finish it,
all that behold it begin to mock him,
Saying, This man began to build, and was not able to finish. 
St. Luke, XIV, 28-30
(The audience was well aware that Jesus' father Joseph
was a carpenter, used to project sizing and materials estimation)

Bardolph: When we mean to build,
We first survey the plot, then draw the model,
And when we see the figure of the house,
Then must we rate the cost of the erection,
Which if we do find outweighs ability
What do we then, but draw anew the model
In fewer offices, or at least desist to build at all? 
William Shakespeare
Henry IV, Part II, Act 1

The same philosophy is outlined, albeit less elegantly, in 20th Century official-speak as follows:

1. A department should consider whether the proposed project
might be too ambitious to be attempted in one go.
2. A department should consider whether their (sic) resources
are adequate to manage the procurement and,
if necessary, limit the project to what they can manage. 

guidelines for PFI developments, 1999

Metrics & Measurement Maxims

To measure is to know. 
Lord Kelvin

If you can not measure it,
you can not improve it. 
Lord Kelvin

Measure twice;
cut once.
The Carpenter's Maxim
(quoted by Roy Tylden-Wright)

No matter how complex the situation,
good systems engineering involves putting value measurements
on the important parameters of desired goals and performance of pertinent data,
and of the specifications of the people and equipment and other components of the system. 
Simon Ramo and Robin St Clair,
The Systems Approach 1998

The number of bugs in a piece of software is constant.
Lehman's Law
Manny Lehman

Not all that counts can be counted;
Not all that can be counted, counts. 
The Metricator's Maxim

Metrics are hard to get
on projects which don't keep records. 
Alexander's 1st Law of Metrics

Modelling Maxims

"We picture facts to ourselves.
A picture is a model of reality.
A picture is a fact.
In order to tell whether a picture is true or false
we must compare it with reality."
Wittgenstein
Tractatus Logico-Philosophicus.

The more creative and flexible an organization is,
the cheaper, simpler, and more numerous are its prototypes. 
Based on Michael Schrage,
Serious Play

The cost of a model is more than compensated for by future savings.
It not only presents an accurate picture of the product for the executives,
but it also gives the tool-makers and production men
an opportunity to criticize and to present manufacturing problems. 
Henry Dreyfuss
Designing for People, p62
Simon & Schuster, New York, 1955

Can ye make a model of it?
If ye can, ye understands it,
and if ye canna, ye dinna! 
Lord Kelvin (supposedly)

.. the first essential step in the direction of learning any subject 
is to find principles of numerical reckoning 
and practicable methods for measuring some quality connected with it. 

I often say that when you can measure what you are speaking about, 
and express it in numbers, you know something about it; 
but when you cannot measure it, when you cannot express it in numbers, 
your knowledge is of a meagre and unsatisfactory kind; 
it may be the beginning of knowledge, 
but you have scarcely in your thoughts advanced to the state of Science, 
whatever the matter may be. 
Lord Kelvin (officially)
This has been quoted by the Robertsons and Tom Gilb inter alia.
However it's so stiff and pompous that I wonder whether
the short version (above) isn't closer to the truth.

Safety Sayings

'Of course it is safe, we certified it'.
An FAA Administrator,
quoted by C.O. Miller,
describing the Paris DC-10's infamous baggage door.

Reliability engineers often assume that reliability and safety are synonymous,
but this assumption is true only in special cases.
Nancy Leveson 

Highly reliable components are not necessarily safe.

Although the fly–fix–fly approach was effective
in reducing the repetition of accidents with identical causes,
it became clear to the Department of Defense (DoD), and later to others,
that it was too costly and, in the case of nuclear weapons, unacceptable
[not] to prevent accidents before they occur the first time.

Software−related accidents are usually caused by flawed requirements.

What [software] must not do is not the inverse of what it must do.

Requirement completeness: Requirements are sufficient to distinguish
the desired behavior of the software
from that of any other undesired program that might be designed.

Safety is an emergent property of systems, not a component property.
Nancy Leveson

System Safety is organized common sense.
George Mueller

Security Sayings, 
Misuse Maxims

You can't calculate the probability that a system is secure
based on the risks it handles,
if it's certain that insecure humans will form part of it. 
 Howard Chivers
Or...
You can't calculate the reliability of a piece of software
if it's certain that its programmers
have put some bugs inside it already.

The most dangerous component in a car
is the nut behind the wheel. 
Urban Wisdom

Quis custodiet ipsos custodes?
But who will you trust to issue the trusted agent certificates to the trusted agents?
The original context is remarkable (an early Misuse Case):
'Lock her up!' you say. 'Put her under guard.'
But who will guard the guards themselves?
Your wife is cleverer than you, and she will begin with them. 
Juvenal

Scenario, Story, & Use Case Sayings

Our brains are patterned for storytelling.
Doris Lessing

Squirrels are just Rats with good PR. *
...or...
Use Cases are just Requirements with good PR.
Urban Wisdom
(repeated by Anthony Kesterton of IBM Rational, 2006)
* Public Relations

Even if we are present at some historic event,
do we comprehend it —
can we even remember it —
until we can tell it as a story?
And for events in times or places
outside our own experience,
we have nothing to go on
but the stories other people tell us.

When you construct or reconstruct a world ..
you look at what happens and try to see why it happens,
you listen to what the people there tell you and watch what they do,
you think about it seriously, and you try to tell it honestly,
so that the story will have weight and make sense. 
Ursula Le Guin
Foreword to Tales from Earthsea, 2001

User stories start the process by writing down just two pieces of information:
each goal to be satisfied by the system and the rough cost of satisfying that goal.
Putting a price on features early encourages prioritizing from the beginning
instead of a panicked abortion of scope at the end to meet a delivery date. 
Kent Beck, Foreword to User Stories Applied,
Mike Cohn, 2004

All the World's a Stage,
and all the Men and Women merely Players:
They have their exits and their entrances;
And one man in his time plays many parts. 
William Shakespeare
As You Like It, Act 2, scene 7

All we know is embodied in stories.
We understand everything in terms of stories we already know. 
Roger C. Schank
Tell Me A Story, 1990

One step at a time. 
Traditional English Saying.

A journey of a thousand miles begins with a single step. 
Chinese Proverb.

When we design systems and applications,
we are, most essentially, designing scenarios of interaction. 
John M Carroll
Scenario-Based Design

Scenarios are arguably the starting point for all modelling and design. 
Alistair Sutcliffe (at RE'03)

Bureaucracy always overwhelms vision.
Stories undermine bureaucracy.
But bureaucracy always wins.
Philip Pullman, novelist (1946- )

Software Sayings

When a lot of remedies are suggested for a disease,
that means it cannot be cured.
Anton Chekhov, playwright (1860-1904)

Using <a well-known operating system>
is like kicking a dead whale along a beach.
Prof. Peter J Brown

Every other industry would consider it
an extremely unethical practice
to pass on to the customer
products of the levels of quality found in software.
L.N. Rajaram
in The Art of Creative Destruction
by Rajnikant Puranik, Shroff, 2005

Software is the only engineering discipline
in which the equivalent of changing the wing on an airplane
constitutes maintenance. 
Industrial Proverb, quoted by Jim Highsmith
(of the Agile Manifesto)
To which he adds:
note the somewhat deprecating tone.

Software and hard drugs
are the only two professions
that refer to their customers as 'users'. 
Anon.

The determined Real Programmer can write FORTRAN programs in any language.
Ed Post, Tektronix Inc: Real Programmers don't use Pascal
The article in Datamation (29:7, July 1983) satirizes Feirstein's book (itself satirical) on masculinity.

Real Programmers don't need comments -- the code is obvious.
Ed Post, Real Programmers don't use Pascal

Real Programmers don't know how to cook:
grocery stores aren't open at three in the morning.
Real Programmers survive on Twinkies and coffee.
Ed Post, Real Programmers don't use Pascal

System Specification Sayings

If it seems too good to be true,
it probably is.
Urban Wisdom.

One man's meat is another man's poison.
One man's trash is another man's treasure [or cash].
English and American proverbs.

One man's requirement is another man's design.
Al Davis,
Software Requirements: Analysis and Specification, 1990

One man's white box is another man's black box.
Bret Pettichord, www.StickyMinds.com

Similar proverbs in this rich vein (clearly a pattern) include:

One man's garbage is another man's gold.

Where there's t' muck there's t' brass.
American and Yorkshire proverbs,
probably about requirements elicitation.

The human population is divided into two groups:
those who move parts of the earth's surface
from one place on the earth's surface to another;
and those who tell them how to do it. 
Bertrand Russell (1872-1970)

There are two sorts of education,
and two sorts of specification:
Maths, and English.
And I don't like the English sort. 
Anon.

In short, my advice to those about to work top-down
is like Mr Punch's advice to those about to marry:
Don't. 
Michael Jackson
'Top-down' in
Software Requirements & Specifications

There is no easy escape
from the human tendency
for top-down problem solving. 
Alistair Sutcliffe
The Domain Theory

We need to be able to work
top down, bottom up and middle every which way. 
Suzanne Robertson

For a successful technology,
reality must take precedence over public relations,
for nature cannot be fooled. 
Richard P Feynman
Nobel Prize-winning Physicist,
during the Challenger inquiry.

I think this has some bearing on our problem. 
Richard P Feynman
after demonstrating that O-ring rubber
went hard in a glass of ice water
during the Challenger inquiry
(showing that the English have no monopoly on understatement).

Le secret d'ennuyer est celui de tout dire.
Voltaire.
  The secret of writing boring specifications
consists of saying everything
in atomic shall statements.

As this is misquoted almost as often as Santayana's dictum,
the context is worth printing:
Et je vais te prouver par mes raisonnements...
Mais malheur à l'auteur qui veut toujours instruire!
Le secret d'ennuyer est celui de tout dire.
C'est ainsi que ma muse avec simplicité
Sur des tons différents chantait la vérité,...  
Voltaire, 
Discours En Vers Sur L'homme,
6th Discourse (On the Nature of Man), line 172, 1737
(3 years after the first 3 discourses)

As far as the laws of mathematics refer to reality, they are not certain;
and as far as they are certain, they do not refer to reality. 
Albert Einstein
quoted by Fritjof Capra,
The Tao of Physics

“In these matters the only certainty is that nothing is certain”
Pliny the Elder (23 - 79 AD)

“When one admits that nothing is certain one must, I think,
also admit that some things are much more nearly certain than others”
Bertrand Russell (1872 - 1970)

All generalisations are dangerous -
including this one. 
Alexandre Dumas,  novelist (1802-1870)

The purpose of war is not battle but victory.
or:
The purpose of analysis is not modelling but understanding. 
Sun Tsu,
The Art of War, ca 500 BC

No part of the delivery process is as critical, nor as difficult -
because requirements map the human world to the technological world. 
Jim Highsmith

Even the word 'users' is an artefact of the [command-and-control] mentality. 
Christopher Locke,
The ClueTrain Manifesto

Everything human is at least a little bit broken. 
David Weinberger
also from The ClueTrain Manifesto

Definition: childproof lock:
a device so secure that the help of a child is required to open it. 
Urban Wisdom

The Americans spent millions of dollars developing a pen that could write in zero gravity.
The Russians gave their astronauts pencils. 
Urban Myth
(The 'space pen' was developed commercially in the USA.
It was supplied at the same bulk-order discount to both space agencies.) 

You want a $100m system by next month
with no defined acceptance criteria.
I can build it! 
Richard Stevens (inventor of DOORS)

Stakeholder Sayings

The man who pays the piper calls the tune. 
Traditional English Proverb

Is the Learner a Computer Peripheral?
Julian Hilton, 1987

The two most important parts of a computing system
are the users and their data, in that order. 
Neville Holmes
Computer, Nov 2004

Well, this is one standpoint. Where is the next?
One should try all things and choose the best. 
Peer Gynt, Act 5, Scene 5, by Henrik Ibsen

(Pulls off several layers at once.)
What an enormous number of swathings!
Isn't the kernel soon coming to light?
(Pulls the whole onion to pieces.)
I'm blest if it is! To the innermost centre,
it's nothing but swathings-each smaller and smaller.
- Nature is witty!
(Throws the fragments away.)  
Peer Gynt, Act 5, Scene 5, by Henrik Ibsen
(explaining the Onion Model of Stakeholders)

Tacit Knowledge

When we pressed him, he stared at us and couldn't answer;
for he'd been in the vision, you see -
he'd been seeing the shape of things, the pattern;
and it's little of that can ever be put in words, and less into ideas.
He knew no more what to think of what he'd said than the rest of us.
But it was all we had.
Ursula Le Guin, Tehanu, 1990.

I shall reconsider human knowledge by starting from the fact that
we can know more than we can tell. 
Michael Polanyi (1891-1976)
The Tacit Dimension, 1966

Unarticulated needs are problems or limitations
[that] customers are not even aware of.
They are intrinsically more difficult to ascertain
and demand real insight into a customer's endeavours.
Herein lies the greatest opportunity: if you discover such a need,
you have a head start in a market with no competition...
 Philip Ruffles, Rolls-Royce Aerospace,
Innovation in aero engines,
The Aeronautical Journal,
1000, 473-484, December 1996

Wovon man nicht sprechen kann,
därüber muss man schweigen.
One must be silent about the things one cannot express.
Alternatively:
If you don't know what you want,
at least keep your mouth shut.
(With apologies to Tom Lehrer) 
L.Wittgenstein,
Tractatus Logico-Philosophicus

Civilisation advances by extending
the number of important operations
we can perform without thinking. 
Alfred North Whitehead
(C20th philosopher/mathematician)

Truths about Tools

A box of crayons and a big sheet of paper
provide a more expressive medium for kids
than computerized paint programs.
Clifford Stoll
To which we can add [kids] - of all ages.

Paper is completely noiseless,
it doesn’t consume any standby power, it won’t
crash, it doesn’t glare, it doesn’t catch viruses,
it won’t heat the room, and it won’t give you a
repetitive-stress injury.
Diomidis Spinellis,
Software, Nov-Dec 2007

Stay with each tool as long as possible. 
(F.M.Lind)
The Dentist's Maxim

If you are using a requirements tool,
find a way to make the story shine through. 
Alistair Cockburn
Writing Effective Use Cases

Investing in putting bad requirements into management tools
is a lot like rearranging the deck chairs on the Titanic. 
Ivy Hooks

The sad reality is that most users of IT in the business space
have barely moved beyond simple file and print. 
Jon Honeyball
(PC Pro, Dec 2004)

Testing Truths

You want a $100M system by next month with no acceptance criteria.
I can deliver it!
Richard Stevens

Tests are no substitute for specifications.
Bertrand Meyer

A testing strategy's most important property
is the number of faults it uncovers as a function of time.

Any failed execution must yield a test case,
to remain a permanent part of the project's test suite.

To test a program is to try to make it fail.
Bertrand Meyer
(Computer, Aug 2008)

Absence of Evidence
is not Evidence of Absence.
On the Track of Unknown Animals
Bernard Heuvelmans

Testing can show the presence of bugs,
but never their absence.
Edsger Dijkstra

Bugs are found during requirement analysis and simulation,
or if not, then during integration testing,
or if not, in live testing by the users. 
Urban Wisdom.

Malfeasant Maxims

The best way to tell a lie
is to tell most of the truth.
The Liar's Maxim

“Use confusing mnemonics.”
Richard Wexelblat

“Have too many special cases.”
Richard Wexelblat

“Release a system early and then make frequent changes.
This most basic tool in the designers’ and implementors’ repertoire requires no discussion.
 
A corollary is the system implementor’s maxim:
let the user do the testing and debugging.”
Richard Wexelblat

  “Improve the [programming] language.”
Richard Wexelblat

“Churchill said
‘Beware of needless innovation, especially when guided by logic.’”
Richard L Wexelblat,
Maxims for Malfeasant Designers, ICSE 1976, pages 331-336.
Wexelblat’s Maxims spawned many admirers and imitators.

“Remember that form is more important than content:
Make sure your visuals conform to corporate standards,
even if they don't say anything of consequence.”
Norman Ramsey,
Maxims for Malfeasant Speakers

“The first deadly sin is to code before you think.”
Peter J. Brown, 13 Deadly Sins of Compiler Writing
That sin is certainly as prevalent today as ever it was.

Never put a requirement in a paragraph all by itself!
"Colin Codephirst",
From the Horse's Mouth, Software, Nov-Dec 2007

A Proof
1.Nothing is better than a meal at the Manoir au Quat'Saisons.
2. Anything is better than nothing.
3. Well, here's a dried-up sandwich from the flight yesterday: it's something.
4.  A dried-up sandwich is better than a meal at the Manoir.
Alexander's Brief Syllogism on Formal Logic in Natural Language

Shoes must be worn
and
Dogs must be carried. 
seen by Michael Jackson
Notices (with rather different meanings)
at the foot of an escalator in an airport