Regulatory pressure on major banks to overhaul their ageing core banking platforms is set to intensify after the Reserve Bank revealed a sharp spike in service outages last year.In a speech to the Central Bank Payments Conference in Berlin on Tuesday evening, RBA Assistant Governor Michelle Bullock referred to new data showing that total downtime of retail banking outages in 2018 more than doubled to around 1800 hours.According to the central bank, there were more than 300 service disruptions at Australian banks and other financial institutions in the 12 months to the end of December - up from about 200 incidents in the previous year.However, the average duration of outage events ballooned to six hours from four hours, with around half of all service disruptions paralysing mobile and online banking channels.Bullock said the increasing complexity of the IT environment in Australian banks was an "important reason" why it was taking longer to resolve outages."Ultimately, it is in the interests of financial institutions to ensure that their systems are resilient," she told the conference."But if some institutions are not keeping pace, they can have adverse effects, not only on their own customers, but also the customers of other financial institutions."Bullock and other senior RBA officials have grown impatient this year with the length of time taken by major banks to hook their systems into the New Payments Platform and to provide modern services such as least cost routing on contactless debit transactions.Bullock sent another firm signal last night that the RBA was now considering action it could take to expedite improvements to banking architecture across the system."So, there is, in our view, a case for the Reserve Bank to be looking at what it can do to encourage improved operational resilience," she said."As a first step, we will be working with the industry and our prudential regulator, the Australian Prudential Regulation Authority, to produce a standard set of operational performance statistics for retail payment to be disclosed by individual institutions."We will also be engaging more with institutions to better understand the challenges of their IT systems and how they are managing operational risks to payment systems."Earlier this month the RBA flagged new powers for NPP Australia to levy fines on banks that fail to upgrade their technology systems in a timely manner to support the roll out of new generation banking services.The operation of the NPP has been retarded by delays in the major banks bringing online and mobile functionality to retail and business customers.While the RBA has not released institution-specific data on outages, the website www.downdetector.com reports there were more than 50 separate service disruptions at ANZ in 2018 and 33 incidents at Commonwealth Bank (excluding Bankwest).There were 25 incidents at the National Australia Bank and 17 at Westpac (excluding its regional banking subsidiaries).Down Detector is a real time service that uses artificial intelligence to monitor social media posts by bank customers.According to Down Detector customers reported fewer incidents at some banks in 2018.They include ME Bank, which had three