Maintaining my PR application status

First, let me clear up a common miscopnception here:

Your PR status does NOT expire after 5 years, only your re-entry permit does.

It is possible to stay in Singapore as PR indefinitely without re-entry permit, as long as you never leave the country! (Whether that is practical, in such a small country, is of course another matter.)

If you got your PR through the PTS scheme (meaning because you worked here long enough) and worked, paid tax (and CPF if applicable) for three of the five years, then your re-entry permit is renewed without further questions asked.

If you did not, they will need additional information to evaluate your commitment to Singapore. Thus the interviews. If you are studying to further your career in Singapore, you have good chances to be approved.

(Note: PRs by family ties, e.g. being married to a Singaporean, get their re-entry permit renewed without such conditions - and sometimes even while living abroad.)

@beppi I see, thanks Beppi.

It is possible to stay in Singapore as PR indefinitely without re-entry permit, as long as you never leave the country! (Whether that is practical, in such a small country, is of course another matter.)

Sorry, I still haven't understand this. You mean literally never leave the country? as in I leave for 1 week vacation and go back to SIngapore, my re-entry permit will start to expire 5 years from that vacation?

If your Re-Entry Permit expires while you're still physically in Singapore, you're still considered a PR. If your Re-Entry Permit expires while you're not physically in Singapore or that you left Singapore without renewing your permit, you would not be able to return to Singapore as a PR but only as a visitor.