Thanks PeacefulDiscord for this useful post, just back from SIRIM office. The details provide by kurogane1031 are still same by the date of 04FEB2015.

During the time I was there, only 2-3 person waiting, the officer told me that nowadays most people apply through email, but I'm not sure how fast they will proceed. So if it's urgent, still better to go SIRIM office personally.