On-Time Performance for The World's Airports 2018. Here is the Southeast Asian Rankings
The OAG's On-Time Performance Stars Ratings Programme is an ongoing accreditation programme which awards all airlines and airports a star rating twice yearly based on 12 months' rolling performance.
OAG's annual Punctuality League is available only for the largest airlines (Top 200 based on ASKs, 30,000+ scheduled flights) and airports (min 2.5 million departed seats) - a ranking based on performance in a single calendar year rather than an ongoing accreditation.
The OTP is measured by departures and arrivals that take place strictly less than 15 minutes after scheduled departure/arrival time, including cancellations.
For Southeast Asian airports, herewith are the full details on the OTP performance rate with each number of operations:
Note: *OTP measured June 2017 - May 2018
Source: Asian Correspondent & OAG Official Website