Unit 4

Agile Development Process

Agile Development: Agile manifesto, agility and cost of change, agility

principles, myth of planned development, toolset for the agile process.

Extreme Programming: XP values, process, industrial XP, SCRUM - process

flow, scrum roles, scrum cycle description, product backlog, sprint planning

meeting, sprint backlog, sprint execution, daily scrum meeting, maintaining sprint

backlog and burn-down chart, sprint review and retrospective.

Agile Practices: test driven development, refactoring, pair programming,

continuous integration, exploratory testing versus scripted testing

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Project Execution Traditional Approach

What comes to your mind ???

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Project Execution Traditional Approach

• Big Bang / Code & Fix

• Waterfall 1950 - 1970

• Spiral Model 1980 - 1988 – Incremental

– Iterative

• RAD (Rapid Application Development) 1990

• Agile 2001

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Typical Waterfall

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Agile framework & principles

The concept of iterative and incremental approach to development started away back from 1950s.

• In 1950s – NASA and The United States Department of Defence (DoD) have used the incremental and iterative development (IID) approach.

• In 1960s – the concept of Evolutionary project management (Evo) recommended a one- to two-week iterations, delivery of product in each iteration.

• In 1986 – The “rugby approach” was discussed with dedicated, self-organizing teams. Here a team tries to go the distance as a unit, passing the ball back and forth—may better serve today’s competitive requirements.”

Origin -

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Agile framework & principles

Rugby Approach –

(Photo from www.zimbio.com – Northland club Rugby)

What is “Agility”?

• Effective (rapid and adaptive) response to change!

• Effective communication among all stakeholders!

• Drawing the customer onto the team! Eliminate “us and them” attitude

• Organizing a team so that it is in control of the work

performed!

• Yielding …!

• Rapid, incremental delivery of software!

Agility and the Cost of Change

• A well-designed agile process “flattens” the cost of change

curve

• Allowing a software team to accommodate changes late in a

software project without dramatic cost and time impact.

• You‟ve already learned that the agile process encompasses

incremental delivery.

• When incremental delivery is coupled with other agile practices

• such as continuous unit testing and pair programming the

cost of making a change is attenuated.

Agility and the Cost of Change

An Agile Process

• Is driven by customer descriptions of what is required

(scenarios)!

• Recognizes that plans are short-lived! (some requirements will persist, some will change. Customer priorities will change)

• Develops software iteratively with a heavy emphasis on

construction activities! (Design and Construction activities are interleaved)

• Delivers multiple „software increments‟!

• Adapts as changes occur!

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Agile framework & principles

• Individuals and interactions over processes and tools

• Working software over comprehensive documentation

• Customer collaboration over contract negotiation

• Responding to change over following a plan

The above states that while there is a value in the items on the right,

we value the items on the left more.

Agile Manifesto –

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Agile framework & principles

Individuals and interactions over processes and tools –

• Promotes empowered, self-managing, cross functional teams • Advocates members to collaborate in person to solve a mutual problem • Tools support cannot replace individual interactions

Agile Manifesto –

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Agile framework & principles

Working software over comprehensive documentation

Agile Manifesto –

• Status / progress should be measured on actual working product and not by percentage completion of the functional milestones

• Agile encourages teams for face-to-face communication over documentation which is simpler, faster, and far more reliable

• Documents usually gets out-dated as system design keeps on changing

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Agile framework & principles

Customer collaboration over contract negotiation

Agile Manifesto –

• Customers become an integral part of the development process and not only during contract negotiation and defining specification

• Better way to deliver value instead of a carefully worded contract

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Agile framework & principles

Responding to change over following a plan

Agile Manifesto –

• Agile plans follow more of a rolling wave approach using top-down planning

• Change management is easier when the organization and the customer share a clear understanding of the project’s status

• In plan-driven environments, all requirements are specified up front, broken down to the task level and estimated which is not the case in Agile developments

• Business needs and priorities can shift in the months or even years it can take for a large system to be fully built

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Agile framework & principles

1. Our highest priority is to satisfy the customer through early and continuous delivery of valuable software

2. Welcome changing requirements, even late in development. Agile processes harness change for the customer’s competitive advantage.

3. Deliver working software frequently, from a couple of weeks to a couple of months, with a preference to the shorter timescale

4. Business people and developers must work together daily throughout the project

5. Build projects around motivated individuals. Give them the environment and support they need, and trust them to get the job done

6. The most efficient and effective method of conveying information to and within a development team is face-to-face conversation

12 Agile Principles –

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Agile framework & principles

7. Working software is the primary measure of progress.

8. Agile processes promote sustainable development. The sponsors, developers, and users should be able to maintain a constant pace indefinitely.

9. Continuous attention to technical excellence and good design enhances agility

10. Simplicity—the art of maximizing the amount of work not done—is essential

11. The best architectures, requirements, and designs emerge from self- organizing teams

12. At regular intervals, the team reflects on how to become more effective, then tunes and adjusts its behaviour accordingly

12 Agile Principles –

Myths of Planned Development

Agile

development is

a methodology Agile is

undisciplined

Myths of Planned Development

Agile has no planning

Agile has no documentation

Myths of Planned Development

Agile has no upfront

design/architecture

Agile does not scale

Myths of Planned Development

Agile is just another fad

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Toolset for Agile Process

 The objective of agile development tools is to help in one or more activities in agile development. Due to use of such tools the operational development software can be created rapidly.

 The agile tool set consist of automated support for project planning, use case development, and requirements gathering, code generation and testing.

 Examples :

1) Actif Extreme :- This tool is developed by Microtool. It provides the support for various technical activities.

2) Ideogramic UML :- it is developed by Ideogramic. This tool is used with agile process.

3) Together Tool Set :- it is distributed by borland. It provides support for technical activities within the XP(extreme programming) and other agile process.

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eXtreme Programming

The most widely used agile process, originally proposed by Kent Beck

in 2004. It uses an object-oriented approach.

 XP Values :- Beck defined the set of five values that serve as a basis for the work performed in the xp. The values are,

1) Communication :- The effective communication must be established between software developers and stake holders in order to convey the important concepts and to get the important feedback.

2) Simplicity :- XP focuses on current needs instead of future needs to incorporate in design.

3) Feedback:- The feedback for software product can be obtained from the developers of software, customers, and other software team members.