バックフィット

noun, noun or participle which takes 'suru'

backfit; retrofit; backfitting; retrofitting

Technical term for modifying existing equipment, systems, or structures to incorporate new features or meet new standards. Used as both a noun and a suru-verb.

• 古ふるい工こう場じょうの機き械かいをバックフィットして、省しょうエネ性せい能のうを高たかめた。

  They retrofitted the old factory's machinery to improve energy efficiency.