Two of its senior executives told a Parliamentary committee last week that 20% of the complex case workload in some departments and companies may be "better handled with some manual intervention".
Their warning to the Work and Pensions subcommittee comes as the Child Support Agency, part of the Department for Work and Pensions, is waiting to transfer one million cases from its old system to a new one built by services giant EDS which simplifies the way calculations are made.
The agency's parent, the Department for Work and Pensions, is undertaking one of the biggest IT-led modernisation programmes in Europe.
In the light of the department's major IT investments, the subcommittee is carrying out an investigation lasting several months into the administration of computer-related projects.
In a briefing paper to the committee, John Corneille, IBM's global relationship partner for the Department for Work and Pensions, and Jan Gower, IBM account executive for the department, wrote that IT systems are "best placed to handle the majority of cases that are relatively straightforward" and "the minority of cases that are highly complex are better handled with some manual intervention".
They added, "This is sometimes known as the 80:20 rule. Accepting that the IT system will not address the minority of highly complex cases allows the system design to be greatly simplified and costs therefore reduced."
The IBM paper also lauded the virtues of commercial off-the-shelf software, which reduces implementation risks, but it warned that an organisation's processes will need to change and end-users will need to accommodate new ways of working.
"The implementation of these changes will be costly, time-consuming and often difficult for users to acceptÉ the difficulty of getting a business ready for a new way of working should not be underestimated," it said.