Agile and Lean Software Development

Agile and Lean
Software Development
Tathagat Varma
Sr. Director
Yahoo!

Discussion Topics

• SDLC
• Waterfall
• Agile
• Lean
• Kanban
• Lean Startup

the world around us…yesterday!

Microsoft Windows timeline

https://en.wikipedia.org/wiki/Timeline_of_Microsoft_Windows

Other major OS and tools timeline

https://en.wikipedia.org/wiki/Solaris_(operating_system) https://en.wikipedia.org/wiki/Bugzilla

A typical support timeline

http://itconvergence.blogspot.in/2012/10/oow-12-elison-extradata-oracle-r122.html

As a contrast, what are consumer
internet companies doing?
• Continuous Integration -> Continuous Delivery ->
Continuous Deployment
• On „good days‟, Flickr releases a new version every half an
hour (Jun 20, 2005)
• IMVU pushes a revision of code to the website every nine
minutes (Feb 10, 2009)
• The other day we passed product release number 25,000 for
WordPress. That means we‟ve averaged about 16 product
releases a day, every day for the last four and a half years!
(May 19, 2010)
• A new version of Google Chrome now due every six weeks
(Jul 22, 2010)
• Facebook does code push twice a day (Aug 4, 2012)

adoption @ net speed!!!

https://lh4.googleusercontent.com/-SQ1ugOgu8Ds/TimaHjH0VpI/AAAAAAAAApU/za0BhEjhoio/w402/google%2Bplus%2Bgrowth%2B20mil.png http://thesamerowdycrowd.wordpress.com/2011/12/26/a-moment-of-our-time/

darwin at work on internet
2006 2009

http://www.flickr.com/photos/stabilo-boss/93136022/sizes/o/in/photostream/ http://rossdawsonblog.com/weblog/archives/2009/05/rapid_turnover.html

yet, our product development sucks!

http://blog.amplifiedanalytics.com/2011/07/musing-on-difference-between-successful-product-innovation/ http://www.nickblack.org/2009/10/how-brand-trust-affects-new-products.html

Let’s understand the ‘craft’ first…
• Sheer joy of making things
• Pleasure of things that are useful to other people
• Fascination of fashioning complex puzzle-like objects of
interlocking moving parts and watching them work in
subtle cycles
• Joys of always learning, which sprints from the non-
repeating nature of the task
• Delight of working in such a tractable medium

The Mythical Man Month – Fred Brooks, 1975

software development life cycles

• Ad-hoc
• Serial
• Iterative
• Incremental
• Iterative/Incremental

notion of ‘progress’ vs. time

Waterfall Model

• Wrongly inspired by assembly-line
manufacturing processes of the day
• Economics supported “measure twice, cut
once” leading to up-front planning and BDUF
• Single-pass, sequential process with hand-offs
and feedback loops between adjoining phases
• Transition to next phase only upon completion
of current phase

Waterfall Software Development

Limitations and Assumptions

1. Wrong analogy: Software development ≠ Production
2. Customers know EVERYTHING upfront and that requirement won’t change
3. Legacy from the past: implicitly assumes CPU time is costly, so focuses on doing
everything upfront to minimize ‘machine time’ for trial and error
4. “Wicked Problem”: Designers and developers know how exactly how to build
5. Very long feedback cycles not suitable for today’s pace of innovation
Picture from http://damonpoole.blogspot.in/2009/07/traditional-development-game-of.html

As a result, software is…

Costly
Buggy
Late

and the costs…?

http://leadinganswers.typepad.com/leading_answers/estimating/
http://www.agileforall.com/dyk/

Holy Grail of Software Development

• Better: higher
quality, more
reliability, higher
performance, more
usable…
• Faster: speedier
development
• Cheaper: no budget
overruns

Preamble to Agile Movement

Software Crisis, 1965-85: The major cause of the
software crisis is that the machines have become
several orders of magnitude more powerful! To put
it quite bluntly: as long as there were no
machines, programming was no problem at all;
when we had a few weak computers, programming
became a mild problem, and now we have gigantic
computers, programming has become an equally
gigantic problem. — Edsger Dijkstra, The Humble
Programmer

Software Crisis
The causes of the software crisis were linked to the
overall complexity of hardware and the software
development process. The crisis manifested itself in
several ways:
• Projects running over-budget.
• Projects running over-time.
• Software was very inefficient.
• Software was of low quality.
• Software often did not meet requirements.
• Projects were unmanageable and code difficult to maintain.
• Software was never delivered.

and the response?

Frameworks, Standards and Certifications

…and the result?…good start…

Why?
The World had changed! Software increasingly
became more business-critical, and delays, cost
overruns and poor quality were significantly less
acceptable then before!

• Process: Long-lead development process ineffective in
a dynamic and global world
• Management: Command and control model
unsuitable for fostering collaboration required to
solve complex problems
• Technology: Advancements in computers, compiler
technology and debugging and testing tools greatly
improved the economics of software development

What is the most important part in these
two machines?

“The Brakes!!!”
They let you go faster…

Agility vs. Discipline?

http://www.ibm.com/developerworks/rational/library/edge/08/feb08/lines_barnes_holmes_ambler/

Advent of Agile and Lean Methodologies
• 1970: Royce critiques Waterfall and offers improvement ideas
• 1986: Barry Boehm proposes Spiral Model
• 1971: Harlan Mills proposes Incremental Development
• 1987: Cleanroom Software engineering
• 1991: Sashimi Overlapping Waterfall Model
• 1992: Crystal family of methodologies
• 1994: DSDM
• 1995: Scrum
• 1996: Rational Unified Process framework
• 1997: Feature Driven Development
• 1999: Extreme Programming Explained
• 2001: Agile Manifesto is born
• 2003: Lean Software Development
• 2005: PM Declaration of Interdependence
• 2007: Kanban-based software engineering
• 2008: Lean Startup
• 2009: Scrumban
• 20xx: Something new !?! (hopefully!)

What is agile really all about?

• Empowered individuals
• Collaboration
Motivated • Democratic decision-making
Individuals and transparency

Self-
organizing • Shorter feedback cycle
x- • Manage changing priorities
functional • Increased productivity
Teams
Agile
Businesses
• Higher ROI
• Faster time to market
• Better User Experience

Why is it so hard?

52 39 34 %
Organizational Culture
%
Resistance to Change
%
Management Support

feedback loop in agile lifecycles

agile lifecycle – big picture

What’s happening here?

http://ayagebeely.blogspot.in/2008_08_01_archive.html

Feedback Loops in Traditional Techniques
vs. Agile Techniques

Agile Development Value Proposition

http://www.versionone.com/Agile101/Agile_Benefits.asp

Does Agile work?

http://www.bigvisible.com/2009/12/taking-agile-beyond-faster/
http://www.testingthefuture.net/page/2/

What is Lean?

• The core idea is to maximize customer
value while minimizing waste. Simply, lean
means creating more value for customers with
fewer resources.
• A lean organization understands customer
value and focuses its key processes to
continuously increase it. The ultimate goal is
to provide perfect value to the customer
through a perfect value creation process that
has zero waste.

Lean Thinking
• Lean thinking changes the focus of management from
optimizing separate technologies, assets, and vertical
departments to optimizing the flow of products and services
through entire value streams that flow horizontally across
technologies, assets, and departments to customers.
• Eliminating waste along entire value streams, instead of at
isolated points, creates processes that need less human
effort, less space, less capital, and less time to make products
and services at far less costs and with much fewer
defects, compared with traditional business systems.
Companies are able to respond to changing customer desires
with high variety, high quality, low cost, and with very fast
throughput times. Also, information management becomes
much simpler and more accurate.

http://www.shmula.com/lean-history-and-timeline-toyota-production-system/5993/

Lean Principles

1. Identify
Value

2. Map
5. Seek
the Value
Perfection
Stream

4.
3. Create
Establish
Flow
Pull

Wastes in Lean

http://nantachit.exteen.com/20120131/muda-muri-mura

How they manifest?

https://leanandkanban.wordpress.com/2011/03/22/lean-is-about-eliminating-waste-right/

Lean Software Development

• Optimize the Whole
• Eliminate Waste
• Build Quality In
• Learn Constantly
• Deliver Fast
• Engage Everyone
• Keep Getting Better

www.poppendieck.com

Optimize the Whole
Optimizing a part of a system will always, over time,
sub-optimize the overall system.

Focus on the Entire Value Stream
From concept to cash.
From customer request to deployed software.

Deliver a Complete Product
Customers don't want software; they want their problems
solved. Complete solutions are built by complete teams.

Think Long Term
Beware of governance and incentive systems that drive short
term thinking and optimize local performance.

Eliminate Waste
Waste is anything that does not add customer value.
The three biggest wastes in software development are:

Building the Wrong Thing
"There is nothing so useless as doing efficiently that which should not
be done at all." –Peter Drucker

Failure to Learn
Many of our policies – for example: governance by variance from
plan, frequent handovers, and separating decision-making from work –
interfere with the learning that is the essence of development.

Thrashing
Practices that interfere with the smooth flow of value –task
switching, long lists of requests, big piles of partly done work – deliver
half the value for twice the effort.

Wastes in Software Development
Wastes in Manufacturing Wastes in Software Development
Inventory Partially done work
Extra Processing Extra processes
Overproduction Extra features
Transportation Task Switching
Waiting Waiting
Motion Motion
Defects Defects

Build Quality In
If you routinely find defects in your verification process, your process is
defective.

Final Verification Should Not Find Defects!
Every software development process ever invented had as its primary
purpose to find and fix defects as early in the development process as
possible.

Mistake-Proof your Process with Test-First Development
Tests – including, unit tests, end-to-end tests, and integration tests –
must be available to establish confidence in the correctness of the
system at any timeduring development, at every level of the system.

Break Dependencies
System architecture should support the addition of any feature at any
time.

Learn Constantly
Planning is useful. Learning is essential.

Predictable Performance is Driven by Feedback
A predictable organization does not guess about the future and call it a
plan; it develops the capacity to rapidly respond to the future as it
unfolds.

Maintain Options
Think of code as an experiment – make it change-tolerant.

Last Responsible Moment
Learn as much as possible before making irreversible decisions. Don't
make decisions that will be expensive to change before their time –
and don't make them after their time!

Learn Fast
Start with a deep understanding of all stakeholders and what they will
value. Create a steady, even flow of work, pulled from this deep
understanding of value.

Rapid Delivery, High Quality, and Low Cost are Fully Compatible
Companies that compete on the basis of speed have a big cost
advantage, deliver superior quality, and are more attuned to their
customers' needs.

Queuing Theory Applies to Development, not Just Servers
Focusing on utilization creates a traffic jam that actually reduces
utilization. Drive down cycle time with small batches and fewer things-
in-process. Aggressively limit the size of lists and queues

Managing Workflow is a lot easier than Managing Schedules
The best way to establish reliable, predictable deliveries is to establish
reliable, repeatable workflows with iterations or a kanban system.

Keep Getting Better
Results are not the point – the point is to develop the people and the
systems capable of delivering results.

Failure is a Learning Opportunity
The most reliable performance comes when even small failures are
deeply investigated and corrected; when noise is not tolerated.

Standards Exist to be Challenged and Improved
Embody the current best known practice in standards that everyone
follows, while actively encouraging everyone to challenge and change
the standards.

Use the Scientific Method
Teach teams to: establish hypotheses, conduct many rapid
experiments, create concise documentation, and implement the best
alternative.

Engage Everyone
The time and energy of bright, creative people are the scarce resources in
today's economy, and the basis of competitive advantage.
People who are paid fairly and adequately are motivated by
autonomy, mastery, and purpose.

Autonomy
The most effective work groups are semi-autonomous teams with an internal
leader with end-to-end responsibility for complete, meaningful tasks.

Mastery
Respect for people means providing the challenge, feedback, and
environment that enables everyone to become excellent.

Purpose
Tie work to value. Only by believing in the purpose of their work will people
become engaged in achieving that purpose.

Kanban System

http://www.toyota-global.com/company/vision_philosophy/toyota_production_system/just-in-time.html

How Kanban helps achieve “Just-
in-Time”
• For example, to efficiently produce a large
number of automobiles, which can consist of
around 30,000 parts, it is necessary to create a
detailed production plan that includes parts
procurement. Supplying "what is
needed, when it is needed, and in the
amount needed" according to this production
plan can eliminate waste, inconsistencies, and
unreasonable requirements, resulting in
improved productivity.
http://www.toyota-global.com/company/vision_philosophy/toyota_production_system/just-in-time.html

Kanban for Software
• Visualize the Workflow: Represent the work items
and the workflow on a card wall or electronic board
• Limit Work-in-Progress (WIP): Set agreed upon
limits on how many work items are in progress at a
time
• Measure and Manage Flow: Track work items to
see if they are proceeding at a steady, even pace
• Make Process Policies Explicit: Agree upon and
post policies about how work will be handled
• Use Models to Evaluate Improvement
Opportunities: Adapt the process using ideas from
Systems Thinking, Deming, etc.
Kanban: Successful Evolutionary Change for your Technology Business – David Anderson

Why Kanban in Software
Engineering?

Don’t build
Don’t write Don’t write Don’t test
features that
more specs more code more code
nobody
than you can than you can than you can
needs right
code test deploy
now

https://leanandkanban.files.wordpress.com/2009/04/kanban-for-software-engineering-apr-242.pdf

Lean Startup Principles
The Lean Startup method teaches you how to
drive a startup-how to steer, when to turn, and
when to persevere-and grow a business with
maximum acceleration.

• Entrepreneurs are everywhere
• Entrepreneurship is management
• Validated Learning
• Innovation Accounting
• Build-Measure-Learn

does iterating help?

http://viniciusvacanti.com/2011/12/12/when-do-you-throw-in-the-towel-on-your-struggling-project/

are small teams more productive?

http://drewcrawfordapps.com/2.0/the-agility-of-small-teams/

does colocation impact team performance?

http://sloanreview.mit.edu/the-magazine/2009-summer/50412/how-to-manage-virtual-teams/

is small batch size faster?

http://www.andrejkoelewijn.com/wp/2011/06/30/is-team-productivity-a-responsibility-of-the-product-owner/

Recap
• Agile ≠ Faster, but Sooner
• Agile ≠ No planning, but Adaptive Planning
• Agile ≠ More work, but ‘Done’
• Agile ≠ No documentation, but Just Enough
• Lean ≠ Cut the corners, but Reduce Waste
• Agile or Lean don’t just change the development
process, but enable a radical change in
organizational culture, leadership and
management practices that is more in line with
business needs and social values and norms of
today

References
• http://butunclebob.com/ArticleS.TimOttinger.MoreWork
• http://butunclebob.com/ArticleS.TimOttinger.SoonerNotFaster
• http://www.toyota-
global.com/company/vision_philosophy/toyota_production_system/jidoka.html
• http://www.toyota-
global.com/company/vision_philosophy/toyota_production_system/just-in-
time.html
• http://www.danube.com/docs/Intro_to_Agile.pdf
• http://codebetter.com/darrellnorton/2005/02/02/lean-software-development-
overview/

It’s not about the method!
• A photographer went to a
socialite party in New York.
As he entered the front
door, the host said „I love
your pictures – they’re
wonderful; you must have a
fantastic camera.‟
• He said nothing until dinner
was finished, then: „That was
a wonderful dinner; you must
have a terrific stove.‟
– Sam Haskins
http://www.haskins.com/ImageShop/Image_Shop_60s/60s_Books_A.Image_01.html

Connect

Blog: http://managewell.net
Email: Tathagat.Varma@gmail.com
Slides: http://slideshare.net/managewell
Twitter: http://twitter.com/TathagatVarma
My Articles: http://managewell.net/?page_id=2

Agile and Lean Software Development

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