testing

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From Perfect Software and Other Illusions About Testing

You have to know what you're expecting before you give meaning to a test report, otherwise everything looks or sounds right. That's why I'm a strong advocate of the test-first philosophy, whereby developers write their tests to include expected results before they write a line of code. It's what we did fifty years ago, but the practice was gradually lost when industry trends separated testing from development.

From Test-driven Development for Embedded C

TDD helps you go faster... Slowing down is exactly what is needed to go fast!

One test result is worth 1,000 expert opinions. [Wernher von Braun]

From Quality Software Management: Vol 4. Anticipating Change

Testing to improve, not to prove.

Testing is not a stage, but part of a control process embedded in every stage.

From The Lady Tasting Tea

What I discovered working at Pfizer was that very little scientific research can be done alone. It usually requires a combination of minds. This is because it is so easy to make mistakes.

No test can be powerful against all possible alternatives.

From Mind and Nature

Other things being equal (which is not often the case), the old, which has been somewhat tested, is more likely to be viable than the new, which has not been tested at all.

From Management of the Absurd

We need to fail often. If we don't, it means we're not testing our limits.

From The Right Stuff

In the military they always said "flight test" and not "test flying".

What people were seeing on television were, in fact, ordinary test events. Blown engines were par for the course in testing aircraft prototypes and were inevitable in testing an entirely new propulsion system, such as jet or rocket engines.

From We Seven

A test-pilot is fiercely proud of his profession. [Walter Schirra]

In combat, for example, you are thinking about what goes on outside of your airplane… But in test flying you have an entirely different problem. You are concerned about what is going on inside the airplane, and what the aircraft itself is doing. [Deke Slayton]

Each part that goes into the capsule has had a prototype tested to destruction to make sure it can stand the rough ride and the temperature changes. The test procedures are extremely painstaking. First, one part is tested; then two parts are linked together and both of them are tested as a unit. The small units are joined into bigger units for further testing, and this process continues until finally the entire machine is ready for a master test. [Malcomn Scott Carpenter]

From The Pragmatic Programmer

Design to Test.

From The Alchemist

'I had to test your courage,' the stranger said. 'Courage is the quality most essential to understanding the Language of the World.'

From The Importance of Living

We must give up the idea that a man's knowledge can be tested or measured in any form whatsoever.

From The Mind of War

He was always testing the limits - of airplanes, people, science, the military, and, most especially, bureaucracies.

From An Introduction to General Systems Thinking

"Proof" in its original sense was a test applied to substances to determine if they are of satisfactory quality... Over the centuries, the meaning of the word "prove" began to shift, eliminating the negative possibilities...

From Safer C

You can't test quality into software.

From The Mythical Man Month

No part of the schedule are so thoroughly affected by sequential constraints as component debugging and system test.

hierarchy

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From Management of the Absurd

The introduction of highly participative systems tends to bring attacks on the stronger members, often the leaders, while more hierarchical systems bring attacks on the weaker members.

It is only when the balance of power is relatively equal that truly candid communication can and should take place.

From The Psychology of Computer Programming

If egoless programming is used, everyone in the group will have the opportunity to examine the work of everyone else at some time, thereby tending to prevent the establishment of strong hierarchy.

From Not Always So

When you practice your own practice together with others, the true ego-lessness happens.

From Situated Learning - Legitimate Peripheral Participation

The fact that the work was done in an interaction between members opened it up to other members of the team.

From Pair Programming Illuminated

Widespread use of pair programming involves a cultural shift in values of the organization - away from individual and toward team recognition and goals.

From Kanban

High-trust cultures tend to have flatter structures than lower-trust cultures.

From Peopleware

The structure of a team is a network not a hierarchy.

From Freedom from Command and Control

Without doubt the most important system condition affecting performance is measurement. It goes hand in hand with command-and-control hierarchical structure.

From Maverick

A conservative bunch, they adhered to a rigid hierarchy, even when complaining.

From The Starfish and the Spider

This is a book about what happens when there is no one in charge. It's about what happens when there's no hierarchy.

From Mind and Nature

In all hierarchies, it is most undesirable to have direct contact between levels that are nonconsecutive.

From The Fifth Discipline

Hierarchy is antithetical to dialogue, and it is difficult to escape hierarchy in organisations.

From Management 3.0

The hierarchy is needed for authorization; the network is needed for communication.

From Thinking in Systems - A Primer

Among all possible complex forms, hierarchies are the only ones that have had time to evolve.
In hierarchical systems, relationships within each subsystem are denser and stronger than relationships between subsystems.
Hierarchical systems evolve from the bottom up.

people

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From The Secrets of Consulting

It's always a people problem.

From Switch - how to change things when change is hard

What looks like a people problem is often a situation problem.

From Taiichi Ohno's workplace management

Let idle people play rather than do unnecessary work.

From Quality Software Management: Vol 1. Systems Thinking

The software industry tends to focus on tools rather than on people.

People's language often reveals when they believe that they are victims of events, rather than having a choice of reactions to the event. Learn to listen for falsely deterministic key words.

From Nudge

Roughly speaking, losing something makes you twice as miserable as gaining the same same thing makes you happy. In more technical language, people are 'loss averse'... Loss aversion helps produce inertia.

From Adapt - why success always starts with failure

A central point of the corporation, as a legal structure, is that it is supposed to be a safe space in which to fail. Limited liability companies were developed to encourage people to experiment, to innovate, to adapt - safe in the knowledge that if their venture collapsed, it would merely be the abstract legal entity that was ruined, not them personally.

From Being Wrong

When we ask people to look for something specific they develop a startling inability to see things in general.

From Becoming a Technical Leader

If you are a leader, people are your work.

From Measuring and Managing Performance in Organizations

You manage things, and you lead people. You control things, and you release people. [Ed Tilford]

From All I need to know about manufacturing I learned in Joe's garage

Like most computer people would have, he had stayed close to his electronic toy rather than come to the garage to watch the production operation.

From Patterns of Software

My overall bias is that technology science, engineering and company organization are all secondary to the people and human concerns in the endeavor.

From Peopleware

If you find yourself concentrating on the technology rather than the sociology, you're like the vaudeville character who loses his keys on a dark street and looks for them on the adjacent street because, as he explains, "The light is better there."

From The Mythical Man Month

The Mythical Man Month is only incidentally about software but primarily about how people in teams make things.

From The Wisdom of Crowds

People are more overconfident when facing difficult problems than when facing easy ones.

Encouraging people to make incorrect guesses actually made the group as a whole smarter.

From Management of the Absurd

When people feel responsible for handling some situation in which they are, in fact, largely helpless, a dangerous combination of feelings is created: responsibility plus helplessness leads to abuse.

Training makes people more alike... Education... tends to make people different from each other.

From Understanding the Professional Programmer

If you want people to change what they're doing, make sure they are fed back the consequences of what they're doing.

patterns

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From The Nature and Art of Workmanship

No two leaves of the same tree are precisely alike, each is individual: yet every one of them conforms to a recognizable pattern characteristic of the species.

From The Unknown Craftsman

If the material is poor the pattern will suffer.

From Quality Software Management. Vol 1. Systems Thinking

A culture is a self-sustaining pattern that has remarkable powers of resistance to change.

The essence of a pattern is what it can do consistently.

From Quality Software Management: Vol 1. Systems Thinking

A locked-on system tends to hold itself to an existing pattern, even against logical reasons to change. … Lock-ons occur in clusters.

The quickest and surest way to classify organisations into similar patterns is by the way people think and communicate.

From Quality Software Management: Vol 2. First-Order Measurement

One of the most sensitive measures of the cultural pattern of any organization is how quickly it finds and removes problems.

Culture makes its presence known through patterns that persist over time.

From An Introduction to General Systems Thinking

And with this shift in time there occurs a shift in the entity of concern - from an object, a pattern of matter in space, to a behavior, a pattern of events in time. [R.W.Gerard]

From An Ecology of Mind

He was often accused of talking in riddles and never coming to the point. The question he posed "What is the pattern that connects?" was never meant to be answered, because the patterns are changing. It was the act of questioning that he was pushing for. Knowing that the eyes behind that curiosity will be the most apt to give the patterns of connection room to wiggle as they perpetually self correct. And to see the beauty in that process. [Nora Bateson]

From Mind and Nature

To be meaningful - even to be recognized as pattern - every regularity must meet with complementary regularities.

From The Silent Language

A pattern is only meaningful if analyzed on its own level.

From Leverage Points

Self-organization is basically the combination of an evolutionary raw material - a highly variable stock of information from which to select possible patterns - and a means for experimentation, for selecting and testing new patterns.

From Patterns of Software

In most types of abstraction the common pattern is replaced by a name, such as a function name, a macro name, a class name...

Dr Deming

is an excellent book by Rafael Aguayo, subtitled The American Who Taught The Japanese About Quality (isbn 0-671-74621-9). This book is also the source of the story about the coffee roasters. As usual I'm going to quote from a few pages

To improve output, production, sales, profit, quality, or any other important factor, every part of the organization had to improve.

Lowering the number of defects in a stable system can only be achieved by working on the system.

A perfectly good system can be ruined by overadjustment and trying too hard.

Overadjustment of a stable system invariably makes things worse. This deserves a special name - tampering.

We are ruined by best efforts. Best efforts without guidance from profound knowledge are oftentimes tampering, ruining perfectly good systems.

The causes of common cause problems cannot be attacked directly.

Good organization is hardly felt and hardly seen. If it is seen and felt, it is most likely the source of problems and therefore the source of loss.

Deming states unequivocally that merit reviews, by whatever name, including management by objectives, are the single most destructive force in American management today.

Running a company by proft alone is like driving a car by looking in the rearview mirror. It tells you where you've been, not where you are going.

The most important thing to know about any tool, including financial reports, is its limitations.

The usual assumption is that each number is due to one cause.

The specification may call for no more than 20 percent defective beads being delivered, which guarantees exactly 20 percent defectives.

Objective observers will only see what they're trained to see.

Because of excessive competition they have been left unable to compete.

If any of us were to purchase everything in our personal lives based on lowest price, we would soon go broke.

organization

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From Ackoff's Best

Organisms and organisations are systems that usually have purposes of their own. However, the parts of an organism (i.e., hearts, lungs, brain) do not have purposes of their own, but the parts of an organisation do … An organisation with purposeful parts almost inevitably generates internal conflict … An organisation is a system whose major deficiencies arise from the ways its parts interact, not from their actions taken separately.

From Dr Deming

To improve output, production, sales, profit, quality, or any other important factor, every part of the organization had to improve.

From Adapt - why success always starts with failure

A central point of the corporation, as a legal structure, is that it is supposed to be a safe space in which to fail. Limited liability companies were developed to encourage people to experiment, to innovate, to adapt - safe in the knowledge that if their venture collapsed, it would merely be the abstract legal entity that was ruined, not them personally.

From Quality Software Management: Vol 1. Systems Thinking

The quickest and surest way to classify organisations into similar patterns is by the way people think and communicate.

From Quality Software Management: Vol 2. First Order Measurement

One of the most sensitive measures of the cultural pattern of any organization is how quickly it finds and removes problems.

From Quality Software Management: Vol 4. Anticipating Change

Organization inhibits reorganization (Minot's Law).

From Implementing Lean Software Development

The mark of an excellent organization is not that they are without problems; it is that they are without systemic problems.

From Patterns of Software

My overall bias is that technology science, engineering and company organization are all secondary to the people and human concerns in the endeavor.

From Adrenaline Junkies and Template Zombies

Organizational lines exists for control and decision-making. They don't usually exist to accelerate work throughput.

From Understanding the Professional Programmer

Rules are not made to be broken, but neither are they made to be not broken. Rules are made so that the organization operates more efficiently.

From Consilience

Complexity theory can be defined as the search for algorithms used in nature that display common features across many levels of organisation.

From Principles of Product Development Flow

The Marines, and all other elite organisations, maintain continuity in their organisational units.

From The End of Certainty

Once we have dissipative structures we can speak of self-organization.

Order can only be maintained by self-organization.

From Complexity and postmodernism - understanding complex systems

A self-organising system will try to balance itself and a critical point between rigid order and chaos.

From The Tao of Business

Taoism believes in a kind of self-organizing system, that there are patterns to the world and its affairs, and that it is best to let these patterns operate without interference.

From Smart Swarm

Unlike our systems, which are tuned for efficiency, the termites' systems have been tuned for robustness, which they demonstrate by building mounds that are constantly self-healing.

From Linked

The theory of phase transition told us loud and clear that the road from disorder to order is maintained by the powerful forces of self-organization.

From Thinking in Systems - A Primer

This capacity of a system to make its own structure more complex is called self-organization.

From Leverage Points

The ability to self-organize is the strongest form of system resilience. A system that can evolve can survive almost any change, by changing itself.

From Simple and Useable

Simple organization is about what feels good as you're using the software, not what looks logical in a plan.

From Beating the System

Implicit assumptions lead to behaviours that are carried out automatically, without thought, and these behaviours constitute an organisation's or a society's culture.

Most assumptions made in and about organisations usually go unquestioned, and their validity is taken to be self-evident, despite Ambrose Bierce's (1967,289) admonition that "self-evident" means evident to oneself and no one else. "Obvious" does not mean "requiring no proof" but "no proof is desired."

From Pair Programming Illuminated

Widespread use of pair programming involves a cultural shift in values of the organization - away from individual and toward team recognition and goals.

From Peopleware

Most organizations don't set out consciously to kill teams. They just act that way.

From A little book of f-LAWS

The best organisations aim to remove the expectation of compliance and eliminate the fear of getting things wrong.

Organizations fail more often because of what they have not done than because of what they have done.

software blending

Here's a story from the book Dr Deming by Rafael Aguayo.

In the early 1950s, American coffee roasters faced a dilemma. The price of coffee beans had risen dramatically, and they were faced with two distasteful choices: either absorb the increased price, partially or totally, hurting profitability; or pass the cost on to their customers and risk losing market share or having customers switch to other beverages.

They came up with an innovative alternative. The coffee roasters' business consists of buying, ageing, roasting, and blending coffee beans to achieve the desired state and smell. Coffee beans, like all agricultural commodities, are highly variable. Two beans can be quite distinct. Even beans picked at the same time from the same tree can be different. A bean picked from the top of the tree, which receives more sunshine, tastes different than a bean from the bottom of the tree.

Blending is a critical part of the process. The leading roaster of the time tried experimenting with different formulations. It found that gradually changing the formulation, substituting lower quality beans, was unnoticeable to the customer. It begins to slowly change the blend. Every two weeks a few more of the less expensive beans were substituted for the heartier, more expensive ones. Most consumers couldn't notice the difference in coffees bought two weeks apart. But if they had tasted, side by side, two batches made six weeks apart, they would have noticed a slight difference.

In effect, the roaster started training customers to accept an inferior blend of coffee. The other roasters noticed what was going on and responded in kind to avoid losing market share. In a few years the American consumer's standards for a decent cup of coffee were radically altered. The managers did their jobs and enjoyed their bonuses. At the time this response was viewed as a triumph of ingenuity. But a funny thing began to happen. Per capita consumption of coffee began a slow but steady decline. The business stopped growing. The roaster that started it all began to experience profitability problems. It is now part of a huge conglomerate and is still experiencing problems in its coffee business. Consumers have discovered gourmet coffees. But ironically, the coffee drunk by Americans during the 1940s was on a par with what we now call gourmet coffees.

Isn't it great! It reminds me of the Fast Food Fallacy from Jerry Weinberg's The Secrets of Computing:

No difference plus no difference plus no difference plus ... eventually equals a clear difference

I emailed the story to Jerry and he replied:

Great story. Even though I've never had a cup of coffee in my life, I can appreciate the dynamic. Indeed, the same dynamic has occurred over and over. I've written about white bread's deterioration - and now we have "gourmet" breads.

And, I suspect, the same thing is now happening in software - gradually lowering the quality of apps, as expectations lower. Then we will have software selling on the basis of freedom from those annoying bugs. Same thing in security, I think.

kanban - some quotes

Quality Software Management: Vol 4. Anticipating Change

Taiichi Ohno's Workplace Management

Implementing Lean Software Development

Toyota Production System

Taiichi Ohno's Workplace Management

The Principles of Product Development Flow

How to use conscious purpose without wrecking everything

The Systems Bible

The Psychology of Computer Programming

The Mythical Man Month

Agile Development in the Large

Surfing the Edge of Chaos

XP values - some quotes

The Systems Bible

Management of the Absurd

The Conquest of Happiness

Mastery

The Aesthetics of Change

How to use conscious purpose without wrecking everything

The Agile Manifesto

The Systems Bible

time

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From Adrenaline Junkies and Template Zombies

On most development projects, time is a scarcer resource than money.

From Consilience

Consilience among the biological sciences is based on a thorough understanding of scale in time and space.

From Nudge

Self-control issues are most likely to arise when choices and their consequences are separated in time.

From The Principles of Product Development flow

Opportunities get smaller with time, and obstacles get larger.

From Zen and the art of motorcycle maintenance

Impatience is close to boredom but always results from one cause: an underestimation of the amount of time the job will take.

From Kluge

What can evolve at any given point in time is heavily constrained by what has evolved before.

People are more likely to accept falsehoods if they are distracted or put under time pressure.

Organisms tend to value the present far more than the future.

From The End of Certainty

There is a necessary trade off between certainty at a given time for continuity through time.

From How Buildings Learn: Chapter 2 - Shearing Layers

Hummingbirds and flowers are quick, redwood trees slow, and whole redwood forests even slower. Most interaction is within the same pace level.

The dynamics of the system will be dominated by the slow components, with the rapid components simply following along. Slow constrains quick; slow controls quick.

From Agile Development in the Large

Quick feedback should be the first thing you introduce.

From Beating the System

Time is our only absolutely nonrenewable and, thus, most highly valued resource. To place a low value on another's time is to show a lack of respect for that person.

From Hackers and Painters

Paying attention is more important to reliability than moving slowly.

mind and nature

is an excellent book by Gregory Bateson (isbn 1-57273-434-5). As usual I'm going to quote from a few pages:

If you want to understand mental processes, look at biological evolution and conversely if you want to understand biological evolution, go look at mental processes.

How is the world of logic, which eschews "circular argument," related to a world in which circular trains of causation are the rule rather than the exception?

Perception operates only on difference. All receipt of information is necessarily the receipt of news of difference, and all perception is necessarily limited by threshold. Differences that are too slight or too slowly presented are not perceivable.

The universe is characterized by an uneven distribution of causal and other types of linkage between its parts; that is, there are regions of dense linkage separated from each other by regions of less dense linkage.

We should define "stability" always by reference to the ongoing truth of some descriptive proposition.

Notoriously it is very difficult to detect gradual change because along with our high sensitivity to rapid change goes also the phenomenon of accommodation. Organisms become habituated. To distinguish between slow change and the (imperceptible) unchanging, we require information of a different sort; we need a clock.

Stability may be acheived either by rigidity or by continual repetition of some cycle of smaller changes, which cycle will return to a status quo ante after every disturbance.

Every given system embodies relations to time, that is, was characterized by time constants determined by the given whole. These constants were not determined by the equations of relationship between successive parts but were emergent properties of the system.

The shape of what it deposits is determined by the shape of the previous growth.

What characterizes those adaptations that turn out to be disasterous, and how do these differ from those that seem to be benign and, like the crab's claw, remain benign through geological ages?

Above all, in sexual reproduction, the matching up of chromosomes in fertilization enforces a process of comparison. What is new in either ovum or spermatozoon must meet with what is old in the other, and the test will favour conformity and conservation. The more grossly new will be eliminated on grounds of incompatibility.

It is very easy to fall into the notion that if the new is viable, then there must have been something wrong with the old. This view, to which organisms already suffering the pathologies of over rapid, frantic social change are inevitably prone, is, of course, mostly nonsense. What is always important is to be sure that the new is not worse than the old.