The document discusses essential agile engineering practices including test-driven development, continuous integration, pair programming, collective code ownership, relentless refactoring, and others. It provides background on these practices, citing academic research showing benefits like reduced defects, increased initial development time but fewer bugs, and case studies demonstrating up to 90% reduced pre-release defect density from using test-driven development. The document advocates that these practices help produce readable, maintainable code and avoid issues like integration defects and code freezes.

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…a taste of…
Essential Agile
Engineering
Practices
Rob Myers
Agile Roots
19 June 2014

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…a taste of…
Essential Agile
Engineering
Practices
@agilecoach
#AgileRoots
19 June 2014

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Test-Driven
Development
Continuous
Integration
Pair
ProgrammingCollective Code
Ownership
Relentless
Refactoring
Sustainable
Pace
Creative Slack
CRC Cards
ATDD
Mocks
Legacy
Characterization
Tests
Spikes
Emergent Design

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6. five focusing steps
1. Identify the constraint.
2. Exploit the constraint: Maximize efficiency at the
constraint.
3. Subordinate all else to the constraint: Allow the
constraint to set the pace.
4. Elevate the constraint: Invest (wisely) in “more,
better, faster.”
5. Repeat.
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“The results of the case studies indicate
that the pre-release defect density of the
four products decreased between 40%
and 90% relative to similar projects that
did not use the TDD practice.
Subjectively, the teams experienced a
15–35% increase in initial development
time after adopting TDD.”
http://research.microsoft.com/en-us/projects/esm/nagappan_tdd.pdf, Nagappan et al,
© Springer Science + Business Media, LLC 2008

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“Laurie Williams of the University of Utah
…has shown that paired programmers are
only 15% slower than two independent
individual programmers, but produce
15% fewer bugs. Since testing and
debugging are often many times more
costly than initial programming, this is an
impressive result.”
"Agility counts", The Economist, 20 Sep 2001

12. beyond academia
• The obvious:
• Fewer defects.
• Cross-training.
• The subtle:
• Collaboration, courage, & creative
problem-solving.
• Self-control, self-discipline, valuable
breaks, fewer interruptions.
• Readable code, less ego-centric code.
• Fewer “heroes” (a.k.a. single points of
failure).
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“If it’s painful,
do it often.”
-- attributed to Kent Beck, who is not a masochist.

14. so boring, a computer could do it
• What it provides:
• Rapid, automated feedback.
• We know we’re testing/deploying a
version from a stable snapshot.
• Often generates valuable metrics.
• What it helps avoid:
• Dependency integration defects, merge
conflicts, lingering broken builds.
• A need for branching, & branched
releases.
• Code freezes.
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15. a short Continuous Integration recipe
1. A build server.
2. A code repository.
3. A fast suite of automated tests.
4. Build scripts.
5. A Buildmeister.
6. A CI tool (optional, but adds zest)
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Test-Driven
Development
Continuous
Integration
Pair
ProgrammingCollective Code
Ownership
Relentless
Refactoring
Sustainable
Pace
Creative Slack
CRC Cards
ATDD
Mocks
Legacy
Characterization
Tests
Spikes
Emergent Design

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Rob.Myers@agileInstitute.com
http://PowersOfTwo.agileInstitute.com/
@agilecoach