reengineering
engineering redesign of existing systems and structures, or the replacement of an old system with a new one, with the objective of better functionality or adaptation to changed environmental conditions
en-US/ɹiˌɛnd͡ʒəˈnɪɹɪŋ/
engineering redesign of existing systems and structures, or the replacement of an old system with a new one, with the objective of better functionality or adaptation to changed environmental conditions