fall through the cracks

Translations
упасть в трещины
The plan to improve the system fell through the cracks.
План по улучшению системы упал в трещины.
Definitions
To be overlooked, neglected, or forgotten, often due to a lack of attention or an imperfect system; typically refers to people or tasks that are unintentionally missed or not properly addressed.
Words
crack

noun
трещина
fall

verb
падать
fall through

verb
провалиться