For the report, IDC examined the core banking modernisation plans of the 10 largest banks in 12 major markets across Asia/Pacific.

Michael Araneta, associate consulting and research director for IDC Asia/Pacific says: "After lackluster deal-making in the last few years, core banking vendor deal sheets have started to fill out with new and impending projects. We expect at least 32 of the top 120 Asia/Pacific ex-Japan banks to undertake significant changes to their current core banking systems from now to 2015."

These projects include not just whole-of-core transitions but also significant changes to key components of core systems such as chart of accounts, GLs, and loans and deposit systems, as banks look to grow their business through territorial expansion and meet new regulatory demands requiring significant improvements in data management and risk analytics.

Says Araneta: "The problem of disorganised data structures gets more severe for large banks that are growing regional businesses, or super-regionalising. Thus, we say that a gradual and iterative re-architecting of data models will be the best solution, and this will be intrinsic in many core banking projects moving forward."

No one vendor is likely to dominate the market, he says, with the rewards being evenly shared across the leading suppliers in accordance with regional preferences.

A recent report by Celent estimates that around $2 billion of the $4.8 billion spent globally on core systems in 2011 came from Asia Pacific, double the amount handed out in Western Europe and North America.

But contrary to IDC's position, Celent analysts believe that the largest banks are already well on their way with core platform overhauls, with new deals more likely to come from small and mid-size institutions.