olemus
toote, protsessi, ettevõtte vm uurimine ja
otsast peale süstemaatiline paremaks
(näiteks tõhusamaks, lihtsamaks, võimsamaks)
ümberkorraldamine, ümberkavandamine ja/või
ümbertegemine

Wiktionary:
the application of technology and management science to the modification of existing systems, organizations, processes and products in order to make them more effective, efficient and responsive

ülevaateid
https://eng.libretexts.org/Bookshelves/Computer_Science/Programming_and_Computation_Fundamentals/Book%3A_Object-Oriented_Reengineering_Patterns_(Demeyer_Ducasse_and_Nierstrasz)/01%3A_Reengineering_Patterns/1.02%3A_The_Reengineering_Lifecycle

https://en.wikipedia.org/wiki/Business_process_re-engineering

https://en.wikibooks.org/wiki/Introduction_to_Software_Engineering/Reengineering

https://en.wikipedia.org/wiki/Code_refactoring