In agile methodology, requirements are called as user stories and all user stories are divided into sprint wise. For exam 6user stories we have and consider 2 for each sprint. So this will go for 4-6weeks. For every sprint for these 2 user stories we write testplan,test scripts,raising defects if any, test execution. After 4-6weeks of completion this will go for production. Between each sprint we go for retrospective meeting where we discuss above success of previous sprint,any lessons learnt to improve in next sprint. Daily for 4-6weeks we have stand-up call where we say our status of work completed. If any user story is left completed becoz of code issue,change in requirement,test data or environment is not ready then that user story is moved to next sprint which is called sprint backlog. Adv: requirements can be added in between.