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Agile Landscape

Introduction

Agile- denoting “the quality of being agile; readiness for motion; nimbleness, activity, dexterity in motion ” is a group of software development methodologies based on iterative and incremental development, where requirements and solutions evolve through collaboration between self-organizing, cross-functional teams. It is a framework or frame of mind. A practitioner of Agile can use different methodologies within the framework to “do or be” Agile. Agile is our guiding principles that lay the foundation for building better software. In layman language, Agile methodology means cutting down the big picture into puzzle size bits, fitting them together when the time is right e.g. design, coding and testing bits. So, while there are reasons to support both the waterfall and agile methods, reasons such as better adaption of change, launchable product at the end of each cycle, usage of object oriented paradigms, emphasis on user requirements followed by the latter clarifies why many software and web design firms make the more appropriate choice of employing Agile methodology.

The term “Agile Software Development” was introduced in 2001 by Agile Software Development Manifesto published by a group of software practitioners and consultants. The important aspects of this Manifesto are,

Individuals and interactions over processes and tools.
Working software over comprehensive documentation.
Customer collaborations over contract negotiation.
Responding to change over following plan.

Life Cycle

Agile Software development processes are based on iterative and incremental development, where requirements and solutions evolve through collaboration between self-organizing, cross-functional teams.Agile processes use feedback, rather than planning, as their primary control mechanism. The feedback is driven by regular tests and releases of the evolving software.

Process

Agile development involves the following steps:

Project Initiation:Set up and justify the project. Determine initial high level requirements.

Project Plan: Plan out the project, everything after Project Initiation, including whether you're going to have the optional phases.

Elaborate Requirements (optional): Very high level requirements are gathered during Project Initiation. These can optionally be expanded during an phase to Elaborate Requirements. Even is the requirements are "elaborated" they are still high level.

Architecture (optional): The Agile approach is generally design for today and refactor tomorrow (at least in XP)..

Release:A Release is a piece of development where the customer gets some new software. Releases can be from 2 weeks to 6 months, but are usually 3 months long. Release have one or more timeboxes.

Time box:A Timebox is 1 – 6 weeks long, but usually 3 – 4 weeks. The most important thing about a timebox is that the delivery date is fixed.

Various kinds of agile techniques

Different Methodologies

Extreme Programming

ExtremeProgramming is one of many AgileProcesses. It is also known as XP. XP is a disciplined approach to delivering high-quality software quickly and continuously.Extreme Programming(XP) has evolved from the problems caused by long development cycles of traditional development models; it appears to be based on trial and error programming!. It is first started as ‘simply an opportunity to get the job done’ with practices that had been found effective in software development process.

Life cycle

The Extreme Programming life cycle consists of the following phases,

Exploration Phase: In this phase the team performs an architectural spike, during which they experiment with the features to envision the initial architecture.
Planning Phase: This phase focuses primarily on identifying the most critical user stories and estimating the time required to implement it. A release will have one to many iterations, which are typically 2-to-4 weeks .
Iteration phase: During this phase; development iteration phase involves iterative testing of the latest versions and eliminating the bugs based on the customer feedback.
Productionizing Phase: During this phase the code is certified for releases based on the customer approval.

Values

Extreme Programming improves a software project in five essential ways;

Communication: Extreme Programmers constantly communicate with their customers and fellow programmers
Simplicity: They keep their design simple and clean.Thereby Teams perform the minimum work needed to meet requirements.
Feedback: They get feedback by testing their software starting on day one.
Respect: They deliver the system to the customers as early as possible and implement changes as suggested
Courage: Every small success deepens their respect for the unique contributions of each and every team member. With this foundation Extreme Programmers are able to courageously respond to changing requirements and technology.

Advantages:

It is more Customer-focused (it’s all about user stories)
It ensures Quality via frequent testing
Constant focus on identifying and delivering the critical user stories
It results in High visibility on project status
It provides great support for volatile requirements

Disadvantages:

Although XP methodology can result in an improved process which is more efficient more predictable more flexible ,it also has weaknesses such as:

Difficulty coordinating larger teams
Can result in a never-ending project if not managed properly
Tendency to not document thoroughly
Predicting the precise features to be accomplished in a fixed time/budget

Scrum

Scrum Development is a lightweight management framework with broad applicability for managing and controlling iterative and incremental projects of all types. Ken Schwaber, Mike Beedle, Jeff Sutherland and others have contributed significantly to the evolution of Scrum over the last decade. Over the last couple of years in particular, Scrum has garnered increasing popularity in the software community due to its simplicity, proven productivity, and ability to act as a wrapper for various engineering practices promoted by other agile methodologies.

LifeCycle:

Characteristics:

Scrum is a process skeleton that contains sets of practices and predefined roles. The main roles in Scrum are:

1.the “ScrumMaster”, who maintains the processes (typically in lieu of a project manager.

2.the “Product Owner”, who represents the stakeholders and the business.

3.the “Team”, a cross-functional group who do the actual analysis, design, implementation, testing, etc.

Advantages:

It helps in saving time and money.
Fast moving, cutting edge developments can be quickly coded and tested as the bugs can be easily fixed.
Short sprints and constant feedbacks results in easier way to cope with the changes.
Daily meeting helps in evaluating individual productivity. Thereby enhances the productivity of each of the team members.
It is easier to deliver a quality product in a scheduled time.

Disadvantages:

Decision-making is entirely in the hands of the teams. And if the team members are not committed, the project will either never complete or fail.
It is good for small, fast moving projects as it works well only with small team.
Absence of any of the team member during development can have huge inverse effect on the project development.

Crystal family of Methodologies

Crystal methods are considered and described as “lightweight methodologies”. The Crystal family of methodologies views software development as a "cooperative game of invention and communication, with a primary goal of delivering working useful software and a secondary goal of setting up the next game". Crystal promotes early, frequent delivery of working software, high user involvement, adaptability, and the removal of bureaucracy or distractions. Alistair Cockburn, the originator of Crystal, has released a book, “Crystal Clear: A Human-Powered Methodology for Small Teams”.

Crystal Family

Crystal is actually comprised of a family of methodologies,whose unique characteristics are driven by several factors such as team size, system criticality, and project priorities. And they are,

Crystal Clear
Crystal Yellow
Crystal Orange
Crystal Orange Web
Crystal Red
Crystal Maroon
Crystal Diamond
Crystal Sapphire

Crystal Clear is the lightest methodology in the family, suitable for co-located teams of up to 10 people. It is a lower-discipline methodology than XP (1st edition) but also requires some documentation.This Crystal family addresses the realization that each project may require a slightly tailored set of policies, practices, and processes in order to meet the project’s unique

Characteristics

Crystal has seven core properties:

Frequent Delivery
Reflective Improvement
Osmotic Communication
Personal Safety
Focus
Expert Users
Automated Tests
Configuration Management
Frequent Integration.

Feature Driven Development

Feature Driven Development is a model-driven, short-iteration process . It is one of a number of Agile methodsfor developing software and forms part of the Agile Alliance. FDD was originally developed and articulated by Jeff De Luca, with contributions by M.A. Rajashima, Lim Bak Wee, Paul Szego, Jon Kern and Stephen Palmer. The first incarnations of FDD occured as a result of collaboration between De Luca and OOD thought leader Peter Coad. It begins with establishing an overall model shape. Then it continues with a series of two-week "design by feature, build by feature" iterations. The features are small, "useful in the eyes of the client" results. FDD designs the rest of the development process around feature delivery using its best eight practices.

Life cycle

A typical life cycle of a Feature Driven Development can be represented as below,

Characteristics

The eight bets practices of FDD are as follows,

Domain Object Modeling
Developing by Feature
Component/Class Ownership
Feature Teams
Inspections
Configuration Management
Regular Builds
Visibility of progress and results

FDD recommends specific programmer practices such as "Regular Builds" and "Component/Class Ownership". FDD's proponents claim that it scales more straightforwardly than other approaches, and is better suited to larger teams. Unlike other agile approaches, FDD describes specific, very short phases of work which are to be accomplished separately per feature. These inc

Advantages

As FDD involves in development of an already thought of an product , rather than examining the market and seeing what the consumer could benefit from.
By using FDD the business sticks solely to what they are good at; they develop goods that fall under an area that they have both experience and knowledge in, creating something that should be, by all accounts, one of the best in its field.
The smaller companies benefit a lot by employing this methodology as they dont have to spend money of technical manpower.

Disadvanatages:

There may be no demand for your product, hence the business will struggle to make money.
It requires a lot of background research on market product before developing.

Adaptive Software Development

Adaptive Software Development is a software development process that grew out of rapid application development work by Jim Highsmith and Sam Bayer. ASD embodies the principle that continuous adaptation of the process to the work at hand is the normal state of affairs. ASD eveolved as the software developer started to revise their management practices. ASD replaces the traditional waterfall cycle with a repeating series of speculate, collaborate, and learn cycles.

Life Cycle

Speculate:

In complex environments, planning is a paradox. "Planning," whether it is applied to overall product specifications or detail project management tasks, is too deterministic a word. It carries too much historical baggage. "Speculate" is offered as a replacement. When we speculate, it's not that we don't define a mission to the best of our ability. So let's be honest, postulate a general idea of where we are going, and put mechanisms in place to adapt

Collaborate:

Managing in a complex environment is scary as hell -- it is also a blast. If we can't predict (plan), then we can't control in the traditional management sense. If we can't control, then a significant set of current management practices is no longer operable, or more specifically, only operable for those parts of the development process that are predictable. Collaboration, in this context, portrays a balance between managing the doing (the main thrust of traditional management) and creating and maintaining the collaborative environment needed for emergence. As projects become increasingly complex, the balance swings much more toward the latter.

Learn:

Collaborative activities build products. Learning activities expose those products to a variety of stakeholders to ascertain value. Customer focus groups, technical reviews, beta testing, and postmortems are all practices that expose results to scrutiny.