Behaviour Driven Development (BDD) is an approach than encourages teams and stakeholders in general to reason about requirements in terms of “executable specifications”, and focus on implementing features with demonstrable business value. BDD is more than just a development technique: in fact, it introduces a whole new dynamic to interactions between team members and stakeholders, a dynamic that increases communication, improves productivity and reduces waste. Through ongoing conversations between business stakeholders and team members, a team applying BDD principles will explore the business goals, capabilities and behaviour that the stakeholders need. They then propose features that the system will need to deliver these capabilities, and use concrete examples and counter-examples to explore and understand these features more fully. In this talk, you will learn about the principles and benefits of BDD for the whole team, how BDD works in practice, and how it affects the various team members in a project. Finally, you will discover the relationship between behavior driven development and automated acceptance testing.

1. Using Behaviour Driven Development to
Enhance Scrum Team Dynamics
John
Ferguson
Smart

2. Consulta
nt
Trainer
Mentor
Author
Speaker
Coder
John Fer
guson S
mar t

3. There are only two problems
in software development
1) Building the software wrong
2) Building the wrong software

4. 50-­‐80%
of
produc.on
code
is
never
or
rarely
used

5. Poor
quality
costs
money!

6. Payroll
System
Ini:al
Budget $6
million
Cost
by
2012 $416
million
Es:mated
cost
to
complete $837
million

7. Payroll
System

8. Project success = right product + built right

9. Building the
right thing
Features aligned
to business needs
Right product,
built right
Wasted effort
Doesn't
do wha
the use t
r wants
What
e
Project lat
Hard to
change
Over bu
sive to
dget
aintain
le
Unstab
Expen
Misaligned
m
requirements
Building the
thing right
How
Poor craftsmanship Quality
Bugs craftsmanship

10. BDD
The Drive for Value

11. Behaviour Driven Development is...
Conversation
Focused

12. Behaviour Driven Development is...
Example-based

13. Behaviour Driven Development is...
i o n
u m pt
A s s

14. Behaviour Driven Development is...
Value Driven

15. Behaviour Driven Development is...
Ou
ts
id
e
In

16. Behaviour Driven Development is...
Business Analyst
A Common
Language
Business Developer
Tester

17. Behaviour Driven Development is...
Executable
Specifications

18. Behaviour Driven Development is...
31%
faster
delivery
Delivery
Time
Tradi.onal
Using
BDD
More value faster

19. Behaviour Driven Development is...
4
.mes
less
defects
Defect
Rate
Tradi.onal
Using
BDD
Higher Quality

20. BDD
A concrete example

21. I
want
to
sell
train
5cket
bookings
online OK.
How
will
that
benefit
you?

22. Travellers
won’t
have
to
waste
8me
queuing
at
the
sta8on
any
more
So
you
might
say:
Yes
In
order
to
save
,me
by
avoiding
the
queue
at
the
sta,on
As
a
traveller
I
want
to
book
my
,cket
online

23. So
why
do
we
care?
People
hate
queueing.
More
Aha!
So
it’s
about
selling
people
will
buy
train
8ckets
if
they
don't
more
8ckets!
have
to
queue.
Yes

24. So
we
could
say
this:
In
order
to
increase
,cket
sales
I
guess
so
As
a
rail
service
I
want
travellers
to
be
able
to
save
,me
by
booking
online

25. Can
you
give
me
an
example
of
how
someone
might
book
a
train
8cket
online?
Sure.
A
traveller
buys
a
8cket
online
from
Dubbo
to
Sydney.
Which
would
cost?
$25
So
we
could
say:
Given
Jane
wants
to
take
a
train
from
Dubbo
to
Sydney
When
she
books
a
,cket
online
Then
she
should
be
charged
$25

26. Hmm.
So
every
traveller
pays
the
same
price?
Of
course
not!
A
pensionner
would
only
pay
$20,
for
example.
Ok.
So
let’s
add
that
example
too:
Given
Joe
wants
to
take
a
train
from
Dubbo
to
Sydney
And
Joe
has
a
pension
card
When
he
books
a
,cket
online
Then
he
should
be
charged
$20
And
he
should
be
issued
with
a
valid
,cket

27. Can
you
give
me
any
other
examples
of
people
who
don’t
pay
$25
for
this
trip?
Yes,
we
give
students
a
30%
discount
Let’s
put
this
in
a
table
Trip base cost Concession type Expected Price
$25 Pensioner $20
$25 Military $20
$25 Student $17.50
$25 Under 12 $12.50
$25 Under 3 $0.00

28. So what did we just do?

29. I
want
to
sell
train
5cket
bookings
online
1) Identify a feature

30. I
want
to
sell
train
5cket
bookings
online
To
increase
5cket
sales
2) Understand why

31. I
want
to
sell
train
5cket
bookings
online
To
increase
5cket
sales
3) Find examples
Given
Jane
wants
to
take
a
train
from
Dubbo
to
Sydney
When
she
books
a
,cket
online
Then
she
should
be
charged
$25

32. I
want
to
sell
train
5cket
bookings
online
To
increase
5cket
sales
4) Challenge assumptions
Given
Jane
wants
to
take
a
train
from
Dubbo
to
Sydney
When
she
books
a
,cket
online
Then
she
should
be
charged
$25
Given
Joe
wants
to
take
a
train
from
Dubbo
to
Sydney
And
Joe
has
a
pension
card
When
he
books
a
,cket
online
Then
he
should
be
charged
$20
And
he
should
be
issued
with
a
valid
,cket

33. I
want
to
sell
train
5cket
bookings
online
To
increase
5cket
sales
5) Extend our model
Given
Jane
wants
to
take
a
train
from
Dubbo
to
Sydney
When
she
books
a
,cket
online
Trip base cost Concession type should
Expected Price
Then
she
be
charged
$25
$25 Pensioner $20
Given
Joe
wants
to
take
a
train
from
Dubbo
to
Sydney
$25 Military $20
And
Joe
has
a
pension
card
$25
Studente
books
a
,cket
online
When
h $17.50
$25
Underh12 hould
be
charged
$20
Then
e
s $12.50
And
he
should
be
issued
with
a
valid
,cket
$25 Under 3 $0.00

34. And now we can automate

35. Now
we
can
automate
the
acceptance
criteria
Trip base cost Concession type Expected Price
$25 Pensioner $20
$25 Military $20
$25 Student $17.50
$25 Under 12 $12.50
$25 Under 3 $0.00
Acceptance criteria

36. Now
we
can
automate
the
acceptance
criteria
Trip base cost Concession type Expected Price
$25 Pensioner $20
$25 Military $20
$25 Student $17.50
$25 Under 12 $12.50
$25 Under 3 $0.00
Automated acceptance criteria

37. Now
we
can
automate
the
acceptance
criteria
Trip base cost Concession type Expected Price
$25 Pensioner $20
$25 Military $20
$25 Student $17.50
$25 Under 12 $12.50
$25 Under 3 $0.00
Living Documentation

38. BDD also applies to coding

39. We are always writing the
specifications for something

40. Low level specifications
Also act as technical documentation

41. High Level BDD
What features should we build?
Automated acceptance criteria
Written for the whole team
Spock
Low Level BDD
How do we build them?
Low level specification and design
Written for developers

42. BDD and the
Product Backlog
A story of focus

43. What should we build next?

44. Backlog Next Sprint
?

45. Backlog Next Sprint
?
$$$$$$$
$$$$$$$
$$$$$$
$$$$$
$$$$
$$$
$$$
$$$
$$$
$$$

46. But what about
Minimum Marketable Features?

47. Backlog Next Sprint
{
?
Minimum $$$$$$$
Marketable
Feature 1 $$$$$$$
$$$$$$
$$$$$
{
Minimum
$$$$
Marketable
Feature 2 $$$
$$$
$$$
$$$
$$$

48. Minimum Marketable Features
or
Minimum Viable Product?

49. How long would it take you to
rewrite your last project?

50. “Ignorance is the constraint”
- Liz Keogh

51. "Ignorance more frequently begets
confidence than does knowledge"
- Charles Darwin

52. Software development is a process of
Continual Incremental Learning
Known
Unknowns
Unknown
Unknowns

53. "Scientia potentia est"
Knowledge is power
- Sir Francis Bacon

54. Learning has value
What stories will reduce our ignorance the most?

55. Backlog Next Sprint
?
$$$$$$$
$$$$$$$
$$$$$$
$$$$$
$$$$
$$$
$$$
$$$
$$$
$$$

56. Backlog Next Sprint
?
???????
???????
??????
?????
????
???
???
???
??
?

57. Hunt
the
value!

58. What do you want to achieve?
Vision What will the business get out of it?
Goals What do users and stakeholders
need to deliver these goals?
Capabilities How can our application
help the users to do this?
We can break a Features
feature up into stories
Stories
Concrete examples are
easier to understand
Scenarios
Are we
there yet? Acceptance Criteria
Code

59. A business goal should
1) Increase Revenue
2) Reduce Costs
3) Protect Revenue
4) Avoid future costs

60. But who knows what the real goals are?
Chances
of
knowing
Senior
Management
Product
Owners
Scrum
Masters
Business
Analysts
Testers
Developers
Role
in
the
organiza8on

61. Every story will provide value to
the business
What makes you so sure?

62. Can you map each story back to a
business goal?

63. Requirements analysis is built on assumptions
Goal
ti on
To
increase
8cket
sale
su mp
revenue As
ti on
u mp
ss
Capability
Sell
8ckets
online A
“Selling tickets
online will increase
sales” Feature
Pay
by
any
credit
card
“More credit card
support will
increase online
sales”

64. How can you validate your assumptions?
Goal
ti on
To
increase
8cket
sale
su mp
revenue As
ti on
Text
u mp
ss
Capability
Sell
8ckets
online A
“Selling tickets
online will increase
sales” Feature
Pay
by
any
credit
card
“More credit card
support will
increase online
sales”
...by measuring the outcomes

65. Impact Mapping
a visual approach to identifying assumptions
Why Who How What
concessions
online booking
To increase travellers take the train
credit card
ticket sale more often
payment
revenue
suggest taking social network
the train to integration
friends

66. 1)
Iden.fy
your
assump.ons
2)
Measure
the
outcomes
3)
Verify
your
assump.ons

67. BDD and team
dynamics
Collaboration like you mean it

68. How do you build
a feature?
Story
WASTE
bug
reports
Working
code
boring
manual
tes5ng

69. How do you build
a feature?
Story
Examples
Automated
acceptance
Shared
criteria
understanding
Working
code
and
Working
Automated
Acceptance
Tests
Exploratory
tes5ng,
usability
tes5ng...

70. Tips and tricks
When the rubber hits the road

71. 71

72. 72
"Don't tell people how to do things, tell them what to
do and let them surprise you with their results"
- George S. Patton

73. 73

74. 74

75. 75
Tailor
your
reporting

76. 76
You
are
allowed
to
ask
ques.ons

77. John
Ferguson
Smart
Questions?