Agile Methods

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Agile Methods

• CIFM03
• Lecture 6

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What is Agile Software Development?

• late 1990's several methodologies gained
  increasing public attention. Theses methodologies
  had a combination of old and new ideas and/or
  transmuted old ideas. These common threads and
  ideas include
• Close collaboration between the programmer, team
  and business experts
• Face-to-face communication (considered to be more
  efficient than written documentation)
• Frequent delivery of new deployable business
  value

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What is Agile Software Development?

• Cohesive and self-organizing teams
• Ways of crafting the code and the team such that
  the inevitable requirements change did not result
  in crises.

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What is Agile Software Development?

• The originators and practitioners of these
  methodologies identified what these methodologies
  had in common
• They coined the word Agile" to name the union of
  these methods
• And, they developed the Manifesto for Agile
  Software Development.

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The Manifesto for Agile Software Development

• Here is the statement of shared development
  values that they identified
• We are uncovering better ways of developing
  software by doing it and helping others do it.
  Through this work we have come to value
• Individuals and interactions over processes and
  tools
• Working software over comprehensive
  documentation
• Customer collaboration over contract negotiation
  
• Responding to change over following a plan
• That is, while there is value in the items on the
  right, we value the items on the left more.

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Implementation of the Manifesto Principles

• http//www.agilemanifesto.org/principles.html
• Many new Agile projects started
• some succeeded and some failed
• There were successes in which business people and
  technical people declared there love for the
  project approach
• This was the way they wanted software development
  done
• And successful projects spawned enthusiasts.

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The Agile Alliance

• The Agile Alliance was born spawned
• To satisfy the customer through early and
  continuous delivery of valuable software
• http//www.agilealliance.org/home

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The Agile Alliance

• The Agile Alliance exists to help more Agile
  projects succeed and to help the enthusiasts
  start Agile projects.

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Agile Alliance

• Emphasises
• Face-to-face communication,
• Visits to a users group and discusions with peers
  about their experiences of Agile methods
• http//www.agilealliance.org/userGroups/index

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History

• http//www.agilemanifesto.org/history.html

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  Agile Database Techniques

• Agile Data (AD) methodology (Data Driven)
• define strategies that apply in a wide variety of
  situations so IT professionals work together
  effectively on the data aspects of software
  systems
• This gives a one size does not fit all
  methodology
• And a collection of philosophies that will enable
  IT professionals to work together effectively on
  the data aspects of software-based systems

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Agile Modelling

• A practice-based methodology for effective
  modelling and documentation of software-based
  systems
• A collection of values, principles, and
  practices for modelling software that can be
  applied on a software development project in an
  effective and light-weight manner (without
  overburdening planning and documentation)
• It is proposed that Agile models are more
  effective than traditional models because they
  are just barely good enough perfection is not
  necessary
• Agile modelling is applicable to requirements
  collection and analysis, architectural design and
  detailed design

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Adaptive Software Development (ASD)

• ASD practices are driven by a belief in
  continuous adaptation
• Using a different philosophy and a different life
  cycle-geared to accepting continuous change as
  the norm
• Replacing the static plan-design-build life cycle
  by a dynamic Speculate-Collaborate-Learn life
  cycle
• Applying a life cycle dedicated to continuous
  learning and oriented to change, re-evaluation,
  predicting (speculating on) an uncertain future
• And, enabling an intense collaboration among
  developers, management, and customers

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Adaptive Software Development (ASD)

• The Speculate-Collaborate-Learn life cycle

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Speculate

• Project Initiation, to set the project's mission
• Establish the Time-Box for the entire project
• Decide on the number of Iterations through
  project development and assign a time-box to each
  one
• Develop a theme or objective for each of the
  Iterations
• Developers and customers both assign features to
  each Iteration

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Collaborate

• The Technical Team delivers working software
• The Project Managers facilitate collaboration and
  concurrent development activities

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Learn

• There are FOUR general categories of things to
  learn about at the end of each development
  iteration
• Resultant Quality from the customer's perspective
  
• Resultant Quality from a technical perspective
• The Functioning of the delivery team and the
  Practices team members are utilizing
• The project's Status

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An ASD life cycles Six basic characteristics

1. Mission focused
2. Feature based
3. Iterative
4. Time-boxed
5. Risk driven
6. Change tolerant

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The Crystal Approach

• A family of human-powered and adaptive,
  Ultralight, Shrink-to-fit software development
  methodologies
• A "Human-powered" approach - focused on achieving
  project success through enhancing the work of
  those involved (other methodologies might be
  process-centric, or architecture-centric, or
  tool-centric, but Crystal is people-centric)
• A Ultralight approach - whatever the project size
  and priorities, a Crystal-family methodology for
  the project will work to reduce the paperwork,
  overhead and bureaucracy to the minimum that is
  practical for the parameters of that project
• A "Shrink-to-fit - start with something seemingly
  small enough, and work to make it smaller and
  better fitting
• Crystal - Non-jealous, that is, allows
  substitution of similar elements from other
  methodologies

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Crystal

• Crystal combines a self-adapting family of
  Shrink-to-fit, Human-powered software development
  methodologies based on the understanding that
• Every project needs a different set of policies
  and conventions, or methodology
• The workings of the project are sensitive to
  people issues, and improve as the people issues
  improve, individuals get better, and their
  teamwork gets better
• Better communications and frequent deliveries
  communication reduce the need for intermediate
  work products

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Feature-Driven Development (FDD)

• FDD starts with creation of a domain object model
  in collaboration with domain experts
• Using information from modelling and from
  requirements activities the developers create a
  features list
• Then a rough plan of development is drawn up and
  responsibilities are assigned
• Then small dynamically formed teams develop the
  features by repeatedly performing design and
  build iterations that last no longer than 2 weeks
  

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At this point Dynamic Systems Development Method
(DSDM)

• The DSDM Lifecycle
• DSDM is more a framework than a method
• The Project Process has 7 phases, which are
  repeated during the life-cycle of the project
  (hence making DSDM an iterative and incremental
  method)

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DSDM

• Pre-Project phase -- ensures that only the right
  projects are started and that they are set up
  correctly.
• Feasibility Study -- assessment of whether DSDM
  is the right approach for the project and a
  definition of the problem, assessments of the
  costs and assessment of the technical feasibility
  of delivering a system.

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DSDM

• Business Study -- the prime focus of attention is
  on the business processes affected and their
  information needs. Using a series of facilitated
  workshops to quickly gain consensus as to the
  priorities of the development.
• Functional Model Iteration -- refining the
  business-based aspects of the system.
• Design and Build Iteration -- is where the system
  is engineered.

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DSDM

• Implementation -- covers the cutover from the
  development environment to the operational
  environment.
• Post-Project -- this phase keeps the solution
  operating effectively.

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Underlying Principles

• Clear definition of roles and responsibilities in
  the project
• Active user involvement is imperative with 4
  defined business roles
• The team must be empowered to make decisions
• The focus is on frequent delivery of products,
  which are defined in terms of purpose and quality
  and who's involved in the delivery

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• 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
• Collaboration and cooperation between all
  stakeholders is essential
• http//www.agilealliance.org/programs/roadmaps/Roa
  dmap/dsdm/dsdm_index.htm

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Lean Software Development

• In the last 25 years, lean thinking has
• had a tremendous global economic impact
• transformed how many industries operate by
  changing the way they think about their work and
  their people.
• Lean works because it produces more wealth by
• eliminating waste,
• enabling any given investment of people and
  productive resources to produce more value while
  providing more meaningful, fulfilling work to the
  participants.
• Lean Software Development applies lean thinking
  to software development contexts.

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Lean

• not about what a team does practices it is
  about how a team decides what to do and when to
  do it.
• starts at the level of principles derived from
  Deming
• The application of lean thinking principles is
  different in each domain and it maps differently
  to different software development contexts as
  well.
• Practices appropriate to lean manufacturing or
  lean construction will not necessarily be
  appropriate to software development.

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Principles (adapted to the software context) are

• Eliminate Waste - If the customer does not value
  it or if it slows down rapid delivery to the
  customer, it is waste. Don't do it.
• Amplify Learning - Development is about discovery
  and feedback. Deliver in small batches to
  minimize uncertainty and permit the customer to
  steer.
• Decide as Late as Possible - Delay commitment.
  Keep options open as long as possible to base
  decisions on the best possible information.

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• Deliver as Fast as Possible - The best measure of
  organizational maturity is the speed with which
  it can repeatedly and consistently deliver value.
  
• Empower the Team - Teams should design their own
  processes. Provide the training and leadership
  they need.
• Build Integrity In - Concurrent development
  enables rich communication, the essential
  ingredient for system integrity.
• See the Whole - Decomposition leads to
  sub-optimization. Focus on overall results.

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• Lean Software Development is not a development
  methodology but rather a way to think about
  whatever approach a team uses.
• Lean Software Development thinking tools support
  team decisions about which practices are
  appropriate in their unique context. Agile
  methods, including Extreme Programming, Scrum,
  DSDM, and Adaptive Software Development, are all
  consistent with the way Lean Software Development
  applies lean thinking to developing software.
• http//www.agilealliance.org/programs/roadmaps/Roa
  dmap/lean/lean_index.htm

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Scrum

• Scrum - an agile, lightweight process that can be
  used to manage and control software and product
  development.
• Wrapping existing engineering practices,
  including Extreme Programming, Scrum generates
  the benefits of agile development with the
  advantages of a simple implementation.
• Scrum significantly increases productivity while
  facilitating adaptive, empirical systems
  development.

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Test-Driven Development

• craft of producing automated tests for production
  code, and using that process to drive design and
  programming.
• For every tiny bit of functionality in the
  production code, you first develop a test that
  specifies and validates what the code will do.
• You then produce exactly as much code as will
  enable that test to pass. Then you refactor
  (simplify and clarify) both the production code
  and the test code.

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In recipe format the steps of TDD are

• The first step is to quickly add a test,
  basically just enough code to fail.
• Next you run your tests, often the complete test
  suite although for sake of speed you may decide
  to run only a subset, to ensure that the new test
  does in fact fail.
• You then update your functional code to make it
  pass the new tests.
• The fourth step is to run your tests again. If
  they fail you need to update your functional code
  and retest.
• Now look for and remove duplication clean up the
  test code (extract common setup into the
  fixture/setUp() split fixtures if they become
  non-cohesive etc.)

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• The above sequence is repeated continuously
  throughout the programming process.
• Each cycle has a duration of minutes, if you're
  not capable to fix a failing test within minutes,
  then throw away the test and the code that you
  wrote to satisfy the test and design a simpler
  test.

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XBreed

• XBreed is the product of mixing SCRUM, XP and
  Alexanderian ideas. XBreed is the result of
  developing multiple applications and shared
  components as fast as humanly possible.
  Combining Scrum and XP is very natural
• Scrum provides a solid management framework,
  while XP provides a basic but complete set of
  engineering practices. The result is a lean but
  very mean (very effective) way to run software
  projects. In addition, Scrum practiced at the
  application team level, and provided a Shared
  Resources Team is involved, can lead to
  reusability.
• http//www.agilealliance.org/programs/roadmaps/Roa
  dmap/xbreed/xbreed_index.htm

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XP - eXtreme Programming

• Extreme Programming is a discipline of software
  development based on values of
• simplicity,
• communication,
• feedback,
• courage.
• Brings whole team together in the presence of
  simple practices, with enough feedback to enable
  the team to see where they are and to tune the
  practices to their unique situation.

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Authors

• Mike Beedle
• Arie van Bennekum
• Alistair Cockburn
• Ward Cunningham
• Martin Fowler
• Jim Highsmith etc
• http//agilemanifesto.org/authors.html

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The new methodology

• Rapidly growing interest in agile (aka
  "lightweight") methodologies.
• Alternatively characterized as an antidote to
  bureaucracy or a license to hack they've stirred
  up interest all over the software landscape.
• reasons for agile methods, focusing not so much
  on their weight but on their adaptive nature and
  their people-first orientation.
• summary and references to the processes in this
  school and consider the factors that should
  influence your choice of whether to go down this
  newly trodden path.
• http//www.martinfowler.com/articles/newMethodolog
  y.html