Agile Software Development

-agil model – agil methodology– agil project management –agil model in software engineering – agil model example -Software engineering -Software engineering –Software engineering concept-Software engineering MCQ -Software engineering Interview Question –Software engineering question paper –free course online –past papers -final year projects for computer science with source code -semester project ideas -computer programming -computer science interview questions- tutorial –cui

Rapid software development

• Rapid development and delivery is now often the most important requirement for software systems
• Businesses operate in a fast–changing environment
• Software has to evolve quickly to reflect changing business needs
• Rapid software development
• User interfaces are often developed using an IDE and graphical toolset

Agile Methods

• The aim of agile methods is to reduce overheads in the software process (e.g. by limiting documentation) and to be able to respond quickly to changing requirements without excessive rework
  • Focus on the code rather than the design
  • Are intended to deliver working software quickly and evolve this quickly to meet changing requirements

Agile Manifesto

• “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;

The principles of agile methods

Principle	Description
Customer involvement	Customers should be involved throughout the development process. Their role is provide and prioritize new system requirements and to evaluate the iterations of the system.
Incremental delivery	The software is developed in increments with the customer specifying the requirements to be included in each increment.
People not process	The skills of the development team should be recognized and exploited. Team members should be left to develop their own ways of working without prescriptive processes.
Embrace change	Expect the system requirements to change and so design the system to accommodate these changes.
Maintain simplicity	Focus on simplicity in both the software being developed and in the development process. Wherever possible, actively work to eliminate complexity from the system.

 

Problems with agile methods

• It can be difficult to keep the interest of customers who are involved in the process
• Team members may be unsuited to the intense involvement that characterizes agile methods
• Maintaining simplicity requires extra work
• Contracts may be a problem as with other approaches

Plan-driven and agile development

Plan-driven development

• A plan-driven approach to software engineering is based around separate development stages with the outputs to be produced at each of these stages planned in advance

Agile development

• Specification, design, implementation and testing are inter-leaved and the outputs from the development process are decided through a process of negotiation during the software development process

Plan-driven and agile specification

Extreme programming

• Perhaps the best-known and most widely used agile method.
• Extreme Programming (XP) takes an “extreme” approach to iterative development
  • New versions may be built several times per day;
  • Increments are delivered to customers every 2 weeks;
  • All tests must be run for every build and the build is only accepted if tests run successfully

The extreme programming release cycle

Extreme programming practices (a)

Principle or practice	Description
Incremental planning	Requirements are recorded on story cards and the stories to be included in a release are determined by the time available and their relative priority. The developers break these stories into development ‘Tasks’.
Small releases	The minimal useful set of functionality that provides business value is developed first. Releases of the system are frequent and incrementally add functionality to the first release.
Simple design	Enough design is carried out to meet the current requirements and no more.
Test-first development	An automated unit test framework is used to write tests for a new piece of functionality before that functionality itself is implemented.
Refactoring	All developers are expected to refactor the code continuously as soon as possible code improvements are found. This keeps the code simple and maintainable.

Pair programming	Developers work in pairs, checking each other’s work and providing the support to always do a good job.
Continuous integration	As soon as the work on a task is complete, it is integrated into the whole system. After any such integration, all the unit tests in the system must pass.
On-site customer	A representative of the end-user of the system (the customer) should be available full time for the use of the XP team. In an extreme programming process, the customer is a member of the development team and is responsible for bringing system requirements to the team for implementation.

Testing in XP

• Testing is central to XP and XP has developed an approach where the program is tested after every change has been made.
• XP testing features:
  • Test-first development
  • Incremental test development from scenarios
  • User involvement in test development and validation
  • Automated test harnesses are used to run all component tests each time that a new release is built

Scrum

• The Scrum approach is a general agile method but its focus is on managing iterative development rather than specific agile practices
• There are three phases in Scrum:
  • The initial phase is an outline planning phase where you establish the general objectives for the project and design the software architecture
  • This is followed by a series of sprint cycles, where each cycle develops an increment of the system
  • The project closure phase wraps up the project, completes required documentation such as system help frames and user manuals and assesses the lessons learned from the project

The Scrum process

The Sprint cycle

• Sprints are fixed length, normally 2–4 weeks. They correspond to the development of a release of the system in XP.
• The starting point for planning is the product backlog, which is the list of work to be done on the project.
• The selection phase involves all of the project team who work with the customer to select the features and functionality to be developed during the sprint.

Scrum benefits

• The product is broken down into a set of manageable and understandable chunks
• The whole team have visibility of everything and consequently team communication is improved
• Customers see on-time delivery of increments and gain feedback on how the product works
• Trust between customers and developers is established and a positive culture is created in which everyone expects the project to succeed

#agilmodel  #agilmethodology #agilprojectmanagement #agilmodelinsoftwareengineering #agilmodel example #Softwareengineering #Softwareengineering #Softwareengineeringconcept #Software engineeringMCQ #SoftwareengineeringInterviewQuestion #Softwareengineeringquestionpaper #freecourse online #pastpapers #finalyearprojectsforcomputersciencewithsourcecode #semesterprojectideas #computerprogramming #computerscienceinterviewquestions #utorial #cui

#courses #pastpaper #Finalyearproject #tutorial #cui #project #programming #computer science #computersciecnemcq’s #computerscienceinterviewquestion