software maintenance
modification of a software product after delivery
software evolution
term used in software engineering to refer to the process of repeatedly updating software, usually used in relation to software maintenance
schema evolution
process of modifying a computer system's data schema while preserving existing data and functionality
Microsoft Software Assurance
Microsoft software licensing and maintenance program aimed at business users that allows business to receive software as well as support and upgrades for the software over the period of a paid subscription
software modernization
updating or porting legacy software to modern practices and platforms