Turkish to English Bus/Financial Accounting

I am translating the Turkish Chart of Accounts from English into Russian.

There is the account GENEL ÜRETİM GİD. VERİM. FARKI
It was translated in the file I am translating as GENERAL OVERHEAD EFFICIENCY VARIANCE.
I’ve looked the term up in a dictionary and found “Productivity differences of general production expenses”.
I’m struggling to understand whether “productivity” or “efficiency” or something else would be correct here.

There is also the account GENEL ÜRETİM GİD. KAPASİTE FARK, which is translated as “capacity differences of general production expenses”, and it makes for me the whole thing even less understandable because I see little difference with “productivity”.

I would be very grateful if anyone provided an explanation.
Please note that I will only understand explanations in English, not in Turkish.