Sand Piles and Software (RailsConf 2012)

Slide 1

Slide 1 text

Sand Piles and Software Zach Dennis

Slide 2

Slide 2 text

The Hobbyist. The Professional. Graphic based on work from photogabble.co.uk

Slide 3

Slide 3 text

Past habits often predict future behavior. Art by Naolito @ DeviantArt

Slide 4

Slide 4 text

tacking on stuff today, probably tacking on stuff tomorrow

Slide 5

Slide 5 text

tests today, probably tests tomorrow

Slide 6

Slide 6 text

refactoring today, probably refactoring tomorrow

Slide 7

Slide 7 text

not today, probably not tomorrow

Slide 8

Slide 8 text

As unpredictable as software is, we are actually quite predictable in producing it.

Slide 9

Slide 9 text

No content

Slide 10

Slide 10 text

No content

Slide 11

Slide 11 text

Falling back into rhythm

Slide 12

Slide 12 text

No content

Slide 13

Slide 13 text

No content

Slide 14

Slide 14 text

Gut feel

Slide 15

Slide 15 text

Gut feel Peer review

Slide 16

Slide 16 text

Gut feel Peer review Tests

Slide 17

Slide 17 text

Gut feel Peer review Tests Metrics

Slide 18

Slide 18 text

Gut feel Peer review Tests Metrics Etc

Slide 19

Slide 19 text

No content

Slide 20

Slide 20 text

what we intuit what often happens

Slide 21

Slide 21 text

No content

Slide 22

Slide 22 text

No content

Slide 23

Slide 23 text

No content

Slide 24

Slide 24 text

No content

Slide 25

Slide 25 text

No content

Slide 26

Slide 26 text

No content

Slide 27

Slide 27 text

No content

Slide 28

Slide 28 text

X software is not linear

Slide 29

Slide 29 text

software is non-linear

Slide 30

Slide 30 text

Software feeds back into itself Sx = ... (Sx - 1)

Slide 31

Slide 31 text

a previous change impacts future changes

Slide 32

Slide 32 text

0.2 compared to 0.2000000001

Slide 33

Slide 33 text

sensitive to conditions

Slide 34

Slide 34 text

sensitive to conditions

Slide 35

Slide 35 text

sensitive to conditions

Slide 36

Slide 36 text

sensitive to conditions

Slide 37

Slide 37 text

sensitive to conditions

Slide 38

Slide 38 text

sensitive to conditions

Slide 39

Slide 39 text

sensitive to conditions Photo by purplerainistaken @ DeviantArt

Slide 40

Slide 40 text

For the want of a nail, the shoe was lost; For the want of a shoe, the horse was lost; For the want of a horse, the rider was lost; For the want of a rider, the battle was lost; For the want of a battle, the war was lost! Art by CSnyder @ DeviantArt

Slide 41

Slide 41 text

Bak-Tang-Wiesenfeld Sand Pile Model

Slide 42

Slide 42 text

No content

Slide 43

Slide 43 text

imagine you’re dropping a grain of sand

Slide 44

Slide 44 text

It la nd sl id e s.

Slide 45

Slide 45 text

self-organized criticality A property of a system that has a critical state (point) as an attractor.

Slide 46

Slide 46 text

Systems can only sustain so much stress.

Slide 47

Slide 47 text

macro from the micro

Slide 48

Slide 48 text

a trigger of any size can cause large-scale change

Slide 49

Slide 49 text

Predicting is hard.

Slide 50

Slide 50 text

http://fc07.deviantart.net/fs12/i/2006/307/4/a/Reading_Rainbow_by_Stingicide.jpg

Slide 51

Slide 51 text

Adding functionality to the system is a bit like dropping a grain of sand.

Slide 52

Slide 52 text

Adding a feature is like dropping multiple grains of sand.

Slide 53

Slide 53 text

Software is attracted to its critical point. critical point attraction Functionality Difﬁculty

Slide 54

Slide 54 text

• The critical point represents a system that can no longer be added to as-is. • The state of the system is REALLY BAD • Development must stop, cleaning must occur. (this isn’t cleaning up as you go, this is waiting for a mess)

Slide 55

Slide 55 text

Oversimpliﬁed Example

Slide 56

Slide 56 text

Real software is more interesting. It has more of everything.

Slide 57

Slide 57 text

Sand Piles and Sand Boxes

Slide 58

Slide 58 text

Many parts of the system.

Slide 59

Slide 59 text

Teams often get caught by starting out at a rapid pace only to be halted not to long thereafter.

Slide 60

Slide 60 text

Big piles.

Slide 61

Slide 61 text

Jagged peaks.

Slide 62

Slide 62 text

The simple act of adding something to the system moves the system closer to its critical point; it’s edge of chaos.

Slide 63

Slide 63 text

The Vicious Stop n Go. Vicious Stop / Go Cycle critical point Functionality Difﬁculty

Slide 64

Slide 64 text

Misconception of Pragmatism

Slide 65

Slide 65 text

Initially, it requires more effort to avoid the critical point than to work towards it.

Slide 66

Slide 66 text

The Vicious Stop n Go. More effort initially. critical point Functionality Difﬁculty

Slide 67

Slide 67 text

The Vicious Stop n Go. Smaller apps get away with it. critical point Functionality Difﬁculty small app large app

Slide 68

Slide 68 text

complexity complexity complexity complexity complexity complexity complexity complexity complexity complexity complexity complexity complexity complexity complexity complexity complexity complexity complexity complexity complexity complexity complexity complexity complexity complexity complexity complexity complexity complexity complexity complexity complexity complexity complexity complexity complexity complexity complexity complexity complexity complexity complexity complexity complexity complexity complexity complexity complexity complexity complexity complexity complexity complexity complexity

Slide 69

Slide 69 text

How do we keep software away from its critical point?

Slide 70

Slide 70 text

Fall in love with simplicity.

Slide 71

Slide 71 text

Loathe complication. ^ unnecessary

Slide 72

Slide 72 text

Champion complexity. show visual of day 0, day 30, day 60, etc.

Slide 73

Slide 73 text

No content

Slide 74

Slide 74 text

No content

Slide 75

Slide 75 text

No content

Slide 76

Slide 76 text

No content

Slide 77

Slide 77 text

No content

Slide 78

Slide 78 text

No content

Slide 79

Slide 79 text

feedback. Listen, feel, respond, learn.

Slide 80

Slide 80 text

Values P r a c t i c e s over

Slide 81

Slide 81 text

If you actively seek ways to exploit your values, practices will come naturally.

Slide 82

Slide 82 text

good bad refactoring

Slide 83

Slide 83 text

good bad writing tests

Slide 84

Slide 84 text

good bad

Slide 85

Slide 85 text

Practices are important but values are at the core of your practices, whether plentiful or lacking, impact every practice you do.

Slide 86

Slide 86 text

Values help determine how we drop our grains of sand.

Slide 87

Slide 87 text

No content

Slide 88

Slide 88 text

May be tough to swallow.

Slide 89

Slide 89 text

If we can afford ourselves the humility to accept it may help us be better served as curators and caretakers of our systems, much like a gardener with their garden.

Slide 90

Slide 90 text

How’s the landscape of your software? twitter: @zachdennis github: zdennis continuousthinking.com mutuallyhuman.com Sand Piles & Software Article in April PragPub