According to MAS Notice 644, a bank shall make all reasonable effort to maintain high availability for critical systems. The bank shall ensure that the maximum unscheduled downtime for each critical system that affects the banks operations or service to its customers does not exceed a total of 4 hours within any period of 12 months (Clause 5).
Bank XYZs banking hours are 9.30 am to 3.30 pm Mon-Fri, has the following systems and incidents in 2020:
System name	Critical system?	Downtime (1)	Downtime (2)	Downtime (3)
Deposit	Y	Apr 10, 2020 (Fri) 10.05-10.25	Oct 5, 2020 (Mon) 9.53-14.32	Dec 25, 2020 (Fri, PH) 8.30-17.00
Lending	Y	Feb 14, 2020 (Fri) 8.20-10.35	[Scheduled] Apr 18, 2020 (Sun) 12.35-16.30	Jun 18, 2020 (Thu) 15.50-19.20
Mobile banking app	Y	[Scheduled] May 7, 2020 (Thu, PH) 0.10-6.00	Sep 18, 2020 (Sat) 12.30-18.00
ATM	Y	[12 ATMs out of 60 ATMs] Jul 15, 2020 (Wed) 9.20-11.30	[Islandwide] Jul 26, 2020 (Sun) 12.37-12.56
What is official downtime of its ATM network reportable to MAS?
150 mins
130 mins
0
20 mins