Agile Methodology: What is Agile Software Development Model?
What is Agile Methodology?
AGILE methodology is a practice that promotes continuous iteration of development and testing throughout the software development lifecycle of the project. In the Agile model, both development and testing activities are concurrent, unlike the Waterfall model.
What is Agile Software Development?
The Agile software development methodology is one of the simplest and effective processes to turn a vision for a business need into software solutions. Agile is a term used to describe software development approaches that employ continual planning, learning, improvement, team collaboration, evolutionary development, and early delivery. It encourages flexible responses to change.
The agile software development emphasizes on four core values.
Individual and team interactions over processes and tools
Working software over comprehensive documentation
Customer collaboration over contract negotiation
Responding to change over following a plan
In this Agile project management tutorial, you will learn-
Agile and Waterfall model are two different methods for software development process. Though they are different in their approach, both methods are useful at times, depending on the requirement and the type of the project.
Agile method proposes incremental and iterative approach to software design
Development of the software flows sequentially from start point to end point.
The agile process is broken into individual models that designers work on
The design process is not broken into an individual models
The customer has early and frequent opportunities to look at the product and make decision and changes to the project
The customer can only see the product at the end of the project
Agile model is considered unstructured compared to the waterfall model
Waterfall model are more secure because they are so plan oriented
Small projects can be implemented very quickly. For large projects, it is difficult to estimate the development time.
All sorts of project can be estimated and completed.
Error can be fixed in the middle of the project.
Only at the end, the whole product is tested. If the requirement error is found or any changes have to be made, the project has to start from the beginning
Development process is iterative, and the project is executed in short (2-4) weeks iterations. Planning is very less.
The development process is phased, and the phase is much bigger than iteration. Every phase ends with the detailed description of the next phase.
Documentation attends less priority than software development
Documentation is a top priority and can even use for training staff and upgrade the software with another team
Every iteration has its own testing phase. It allows implementing regression testing every time new functions or logic are released.
Only after the development phase, the testing phase is executed because separate parts are not fully functional.
In agile testing when an iteration end, shippable features of the product is delivered to the customer. New features are usable right after shipment. It is useful when you have good contact with customers.
All features developed are delivered at once after the long implementation phase.
Testers and developers work together
Testers work separately from developers
At the end of every sprint, user acceptance is performed
User acceptance is performed at the end of the project.
It requires close communication with developers and together analyze requirements and planning
Developer does not involve in requirement and planning process. Usually, time delays between tests and coding
Check below Agile process model to deliver successful systems quickly.
There are various Agile methods present in agile testing, and those are listed below:
SCRUM is an agile development method which concentrates specifically on how to manage tasks within a team-based development environment. Basically, Scrum is derived from activity that occurs during a rugby match. Scrum believes in empowering the development team and advocates working in small teams (say- 7 to 9 members). It consists of three roles, and their responsibilities are explained as follows:
Master is responsible for setting up the team, sprint meeting and removes obstacles to progress
The Product Owner creates product backlog, prioritizes the backlog and is responsible for the delivery of the functionality at each iteration
Team manages its own work and organizes the work to complete the sprint or cycle
This is a repository where requirements are tracked with details on the no of requirements(user stories) to be completed for each release. It should be maintained and prioritized by Product Owner, and it should be distributed to the scrum team. Team can also request for a new requirement addition or modification or deletion
Practices are described in detailed:
Process flow of Scrum Methodologies:
Process flow of scrum testing is as follows:
Each iteration of a scrum is known as Sprint
Product backlog is a list where all details are entered to get the end-product
During each Sprint, top user stories of Product backlog are selected and turned into Sprint backlog
Team works on the defined sprint backlog
Team checks for the daily work
At the end of the sprint, team delivers product functionality
eXtreme Programming (XP)
Extreme Programming technique is very helpful when there is constantly changing demands or requirements from the customers or when they are not sure about the functionality of the system. It advocates frequent "releases" of the product in short development cycles, which inherently improves the productivity of the system and also introduces a checkpoint where any customer requirements can be easily implemented. The XP develops software keeping customer in the target.
Business requirements are gathered in terms of stories. All those stories are stored in a place called the parking lot.
In this type of methodology, releases are based on the shorter cycles called Iterations with span of 14 days time period. Each iteration includes phases like coding, unit testing and system testing where at each phase some minor or major functionality will be built in the application.
Phases of eXtreme programming:
There are 6 phases available in Agile XP method, and those are explained as follows:
Resource planning for both Development and QA teams
Break down of tasks
Test Scenario preparation for each task
Regression Automation Framework
Execution of Manual test scenarios
Defect Report generation
Conversion of Manual to Automation regression test cases
Mid Iteration review
End of Iteration review
Demos and reviews
Develop new stories based on the need
Process Improvements based on end of iteration review comments
SLA Guarantee assurance
Review SOA strategy
There are two storyboards available to track the work on a daily basis, and those are listed below for reference.
This is a traditional way of collecting all the stories in a board in the form of stick notes to track daily XP activities. As this manual activity involves more effort and time, it is better to switch to an online form.
Online tool Storyboard can be used to store the stories. Several teams can use it for different purposes.
Crystal Methodology is based on three concepts
Chartering: Various activities involved in this phase are creating a development team, performing a preliminary feasibility analysis, developing an initial plan and fine-tuning the development methodology
Cyclic delivery: The main development phase consists of two or more delivery cycles, during which the
Team updates and refines the release plan
Implements a subset of the requirements through one or more program test integrate iterations
Integrated product is delivered to real users
Review of the project plan and adopted development methodology
Wrap Up: The activities performed in this phase are deployment into the user environment, post- deployment reviews and reflections are performed.
Dynamic Software Development Method (DSDM)
DSDM is a Rapid Application Development (RAD) approach to software development and provides an agile project delivery framework. The important aspect of DSDM is that the users are required to be involved actively, and the teams are given the power to make decisions. Frequent delivery of product becomes the active focus with DSDM. The techniques used in DSDM are
The DSDM project consists of 7 phases
Functional Model Iteration
Design and build Iteration
Feature Driven Development (FDD)
This method is focused around "designing & building" features. Unlike other agile methods, FDD describes very specific and short phases of work that has to be accomplished separately per feature. It includes domain walkthrough, design inspection, promote to build, code inspection and design. FDD develops product keeping following things in the target
Domain object Modeling
Development by feature
Component/ Class Ownership
Visibility of progress and results
Lean Software Development
Lean software development method is based on the principle "Just in time production". It aims at increasing speed of software development and decreasing cost. Lean development can be summarized in seven steps.
Defer commitment (deciding as late as possible)
Empowering the team
Optimize the whole
Kanban originally emerged from Japanese word that means, a card containing all the information needed to be done on the product at each stage along its path to completion. This framework or method is quite adopted in software testing method especially in agile testing.
Scrum Vs Kanban
In scrum technique, test must be broken down so that they can be completed within one sprint
No particular item size is prescribed
Prescribes a prioritized product backlog
Prioritization is optional
Scrum team commits to a particular amount of work for the iteration
Commitment is optional
Burndown chart is prescribed
No particular item size is prescribed
Between each sprint, a scrum board is reset
A Kanban board is persistent. It limits the number of items in workflow state
It cannot add items to ongoing iteration
It can add items whenever capacity is available
WIP limited indirectly
WIP limited directly
Timeboxed iterations prescribed
Timeboxed iterations optional
Metrics that can be collected for effective usage of Agile is:
Effort in hours which do not contribute to sprint goal
Drag factor can be improved by reducing number of shared resources, reducing the amount of non-contributing work
New estimates can be increased by percentage of drag factor -New estimate = (Old estimate+drag factor)
Amount of backlog(user stories) converted to shippable functionality of sprint
No of Unit Tests added
Time interval taken to complete daily build
Bugs detected in an iteration or in previous iterations