input: [S. No.] 6 Basically, it includes, post production / deployment support & enhancements. Most of people say - Maintenance testing is carried out in this phase. My definition for this is - updation & maintenance of test plans, test case required for the testing of support requests & enhancements as a part of maintenance. [Phase] 
output: Maintenance
options: R e q u i r e m e n t s G a t h e r i n g
options: D e s i g n
options: C o d i n g o r d e v e l o p m e n t
options: T e s t i n g
options: D e p l o y m e n t
options: M a i n t e n a n c e