This reminds me of one particularly intense semester I had at graduate school. Trying to get a design project completed, a lab partner and I spent three days straight at our campus.
At one point in time, the lab director (who liked to run a pretty "tight ship"), looked at our sundry items strewn messily across a table, and said with an annoyed and disgusted voice, "Gee, it looks like someone is living here!"
We were taking an exam at the time, but a friend overheard the remark, and came to our defense, answering, "Actually, sir, I think Greg and Jim haven't been home since Tuesday."
"Oh!" the director replied, "Well, if they are living here, then that's okay."
In any case, if I were describing that situation, I could say:
I had not been home since Tuesday.
or:
I had not gone home since Tuesday.
and either of those would be equally appropriate or correct.
"Been home" implies arriving at my house; "gone home" implies leaving the lab to go home. In this context, these both imply the same thing – leave the lab to go home – so I can say it either way.
The two are interchangeable if you intend a continuative† reading: that you have lived in Europe for the two years leading to the present moment.
okI have lived in Europe for two years, and will not leave until next year.
okI have been living in Europe for two years, and will not leave until next year.
But if you intend an existential† reading, signifying that you lived in Europe for two years on at least one occasion in the past, you cannot use the progressive construction:
okI am widely travelled: I have lived in Europe for two years, in Brazil for nearly five, and in Singapore for three. BUT
∗ I am widely travelled: I have been living in Europe for two years, in Brazil for nearly five, and in Singapore for three.
†For a somewhat more detailed description of these distinct uses of the perfect, see What is the perfect, and how should I use it?, especially §3.2 Pragmatic meaning.
∗ marks an utterance as unacceptable
Best Answer
Both of these sentences are grammatically correct. The difference is the tense.
The first sentence is present perfect. It implies that periodical reviews were performed at an indefinite time in the past and probably this action is still going on now.
When you use present continuous, you are talking about the activities that are happening now and may continue in the future. So in your second sentence you are talking about the periodical reviews that are being performed at the moment and may continue to be done in the future.