2. The Manifesto for
Agile Software Development
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“
“We are uncovering better ways of developing
We are uncovering better ways of developing
software by doing it and helping others do it.
software by doing it and helping others do it.
Through this work we have come to value:
Through this work we have come to value:
•Individuals and interactions
Individuals and interactions over processes
over processes
and tools
and tools
•Working software
Working software over comprehensive
over comprehensive
documentation
documentation
•Customer collaboration
Customer collaboration over contract
over contract
negotiation
negotiation
•Responding to change
Responding to change over following a plan
over following a plan
Kent Beck et al
Kent Beck et al
3. What is “Agility”?
Effective (rapid and adaptive) response to
change
Effective communication among all stakeholders
Drawing the customer onto the team
Organizing a team so that it is in control of the
work performed
Yielding …
Rapid, incremental delivery of software
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5. An Agile Process
Is driven by customer descriptions of what is
required (scenarios)
Recognizes that plans are short-lived
Develops software iteratively with a heavy
emphasis on construction activities
Delivers multiple ‘software increments’
Adapts as changes occur
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6. Extreme Programming (XP)
The most widely used agile process, originally proposed
by Kent Beck
XP Planning
Begins with the creation of “user stories”
Agile team assesses each story and assigns a cost
Stories are grouped to for a deliverable increment
A commitment is made on delivery date
After the first increment “project velocity” is used to help
define subsequent delivery dates for other increments
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7. Extreme Programming (XP)
XP Design
Follows the KIS principle
Encourage the use of CRC cards (see Chapter 8)
For difficult design problems, suggests the creation of “spike solutions”—a design
prototype
Encourages “refactoring”—an iterative refinement of the internal program design
XP Coding
Recommends the construction of a unit test for a store before coding commences
Encourages “pair programming”
XP Testing
All unit tests are executed daily
“Acceptance tests” are defined by the customer and executed to assess customer visible
functionality
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8. Extreme Programming (XP)
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unit test
continuous integration
acceptance testing
pair
programming
Release
user stories
values
acceptance test criteria
iteration plan
simple design
CRC cards
spike solutions
prototypes
refactoring
software increment
project velocity computed
9. Adaptive Software Development
Originally proposed by Jim Highsmith
ASD — distinguishing features
Mission-driven planning
Component-based focus
Uses “time-boxing” (See Chapter 24)
Explicit consideration of risks
Emphasizes collaboration for requirements
gathering
Emphasizes “learning” throughout the process
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10. Adaptive Software Development
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adaptive cycle planning
uses mission statement
project constraints
basic requirements
time-boxed release plan
Requirements gathering
J AD
mini-specs
components implemented/ tested
focus groups for feedback
formal technical reviews
postmortems
software increment
adjustments for subsequent cycles
Release
11. Dynamic Systems Development Method
Promoted by the DSDM Consortium (www.dsdm.org)
DSDM—distinguishing features
Similar in most respects to XP and/or ASD
Nine guiding principles
Active user involvement is imperative.
DSDM teams must be empowered to make decisions.
The focus is on frequent delivery of products.
Fitness for business purpose is the essential criterion for acceptance of deliverables.
Iterative and incremental development is necessary to converge on an accurate business solution.
All changes during development are reversible.
Requirements are baselined at a high level
Testing is integrated throughout the life-cycle.
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13. Scrum
Originally proposed by Schwaber and Beedle
Scrum—distinguishing features
Development work is partitioned into “packets”
Testing and documentation are on-going as the product is
constructed
Work occurs in “sprints” and is derived from a “backlog” of
existing requirements
Meetings are very short and sometimes conducted without
chairs
“demos” are delivered to the customer with the time-box
allocated
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15. Crystal
Proposed by Cockburn and Highsmith
Crystal—distinguishing features
Actually a family of process models that allow
“maneuverability” based on problem characteristics
Face-to-face communication is emphasized
Suggests the use of “reflection workshops” to
review the work habits of the team
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16. Feature Driven Development
Originally proposed by Peter Coad et al
FDD—distinguishing features
Emphasis is on defining “features”
a feature “is a client-valued function that can be implemented in
two weeks or less.”
Uses a feature template
<action> the <result> <by | for | of | to> a(n) <object>
A features list is created and “plan by feature” is conducted
Design and construction merge in FDD
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18. Agile Modeling
Originally proposed by Scott Ambler
Suggests a set of agile modeling principles
Model with a purpose
Use multiple models
Travel light
Content is more important than representation
Know the models and the tools you use to create
them
Adapt locally
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