According to Japanese METI web site on Nov 21, Japanese government was noticed from Singapore government that Certificate of Origin ("CO") for ASEAN-JP EPA will not be issued on December 1, which is the implementation day of ASEAN-Japan EPA.
This is due to Singapore's internal reason, the preparation system is not due on time.
Japan request to Singapore to make effort to issue CO on time as originally announced by Dec 1.
At this time, Singapore will come to issue CO by January 1st, including retrospective issuance.
As for receiving in importing CO as proof of origin, Singapore will accept as originally planned from Dec 1.
(Source: METI web site: http://www.meti.go.jp/policy/trade_policy/081121%20AJCEP発効にあたって〔セット版〕.pdf)