The central bank stressed that all banks should ensure that their critical systems and services to customers are “resilient to disruption”. Photo: Bloomberg

The Monetary Authority of Singapore (MAS) says it has instructed DBS Bank as well as Citibank N.A., Singapore Branch and Citibank Singapore Limited (Citibank) to conduct a thorough investigation on why they were able to fully recover their systems within the required timeframe.

Customers from both banks suffered from service disruptions after their primary data centres failed to perform normally on Oct 14. Both DBS and Citibank subsequently activated their back-up data centres.

MAS adds that it will take the “appropriate supervisory actions” on the banks after gathering the necessary facts on the outage.

“No information technology (IT) system is infallible. Banks and customers should have contingency measures in the event of service disruptions caused by IT outages,” says MAS in its response to media queries on Oct 19.

That said, it recognised that both banks activated their own set of measures such as extending their branch hours and making alternative arrangements for credit card transactions to reduce the impact on their customers.

However, the central bank stressed that all banks should ensure that their critical systems and services to customers are “resilient to disruption”.

“Banks are required to have in place back-up data centres and systems and test them periodically to ensure that critical systems and services can be restored within 4 hours following an outage,” says MAS.

“In addition, the unscheduled downtime for a critical system affecting a bank’s operations or service to customers must not exceed four hours within any 12-month period. MAS does not have oversight of data centres; instead MAS expects banks to establish contractual agreements with data centre providers that incorporate MAS’ requirements on system availability,” it adds.