IT managers need to leave time within electronic project plans to remedy faults revealed by stress testing, industry experts said this week.
The warning follows last week's decision by Halifax bank to postpone the launch of its Internet banking service, Intelligent Finance (IF), only days before it was due to go live.
The launch was pulled because the site slowed down during "stress testing" last Friday. A weekend of further checks left Halifax unable to provide a more detailed explanation for the site's IT problems.
Halifax's decision to delay the launch in the face of performance doubts contrasts with Abbey National's Internet bank Cahoot, whose Web site crashed on the day of its launch.
Software testing experts said the cause of IF's difficulties could range from an integration problem between the Web site and the back-office system to a problem with the system's audit trail.
Garry Clarkson, enterprise technical consultant for Keane, which tested the software for the Co-operative's Internet bank Smile, said, "Stress testing a system is guaranteed to find problems so you need to leave time to change the software."
Internet banking systems should also have a facility to lock people out of the site when response times fall below a pre-set level, added Clarkson.
Halifax now plans to launch IF's telephone banking next month, closely followed by the online service.