Big bang versus a phased approach is a big decision. The former might mean a faster project, so that benefits are realised earlier, but tends to come with heightened risk. At Equity Bank in Kenya, the fact that customers were 'clamouring for improved service' pushed the bank towards a big bang even though, with hindsight, head of operations, AllanWaititu, admitted a phased route would have been preferable.
The flexibility of some packages is notorious for creating problem projects. If you are able to configure everything within a system then this brings great flexibility but also requires firm project management. There are also examples of banks taking pre-configured versions of systems from other bank implementations as the starting point for their own projects. AXA Bank in Switzerland did this. The flexibility can also have performance issues, with this clearly seen within Saudi Hollandi's implementation of Temenos' T24, for instance.
Data migration is often a major challenge but this can be eased if all of the data is already in one core system (as opposed to being consolidated from multiple sources) and also if there are tools from third-parties or the core system provider to automate the process, mapping from old to new formats.
Another issue is sometimes a lack of documentation and understanding of existing business processes. It took Belgazprombank in Belarus a year and a half to resolve this issue, in part because its core system replacement project included a major reengineering effort.
One bank that had fairly severe post-implementation problems was Bank of Queensland. 'Customers who felt they were being let down – combined with staff who didn't have the answers – was probably one of our most serious issues throughout the implementation,' said managing director, David Liddy.
