Purcell estimates that in Australia banks have already invested between A$7 billion (US$5 billion) and A$10 billion on core systems.

Gerd Schenkel, National Australia Bank (NAB) customer strategy and cross-marketing general manager, said the application and exposure of CRM within the NAB has "revealed opportunities for changing the core systems to capture new data to support the expansion of CRM functions".

Schenkel said the main issue for the bank was aligning production schedules to feed data into the CRM system. To do this, core data source systems had to be modified, he said.

While data quality was sufficient when implementing CRM, Schenkel said production schedules for core systems were modified to ensure processes were in place to deliver information at the start of the next business day.