In a full-year 2013 results presentation, the Australian bank laid out a five-year plan to create a common technology backbone with subsidiary bank St George that would pave the way for both banks to move to Celeriti, the latest version of the CSC-managed Hogan platform, which is currently in use at St George.

The plans come three years after the bank ditched an earlier scheme to move to the Hogan platform back in 2010 to concentrate instead on a more pressing near-term Strategic Investment Priorities (SIPs) programme. This entailed the consolidation of the bank's data centres from eight to two, the introduction of new digital signature, IP telephony and customer information systems at the branch and call centre level, and the the build out of an enterprise middleware platform for consolidation of customer information projects.

The upshot is a more reliable system core and savings of A$189 million over the lifetime of the programme, says Westpac. In concluding the SIPs investment, the bank will roll out a new online and mobile banking platform during 2014, which is currently undergoing final testing with 4500 customers.

In committing to a new core renewal programme, Westpac will be playing catch up with rivals National Australia Bank and CommBank. The latter has substantially completed the replacement of its core banking platform and is reaping the rewards in the presentation of a more modern, digital-first approach to customer service that has cut costs and improved customer satisfaction across the board.

Rival big four bank ANZ upgraded its Hogan-based system in the 1990s, but believes that the advantages of an upgrade is overplayed, preferring instead to add new consumer-facing applications at the front-end.

Speaking to Australian Financial Review, ANZ's Australian chief Philip Chronican, said: "I think the [core systems] advantage is overplayed, and the evidence of that is that, having done it, CBA has got no better cost-to-income ratio than we do for the domestic business and we have been growing more quickly than they have... There is more juice to be had out of our existing setup. I can do that without building a core and I can make the core less risky by leaving it for a year or two, then it seems like a fair trade off."