How does Visa complete the complex updates of its global payment network without any system interruptions?
When Visa updates VisaNet, its global transactions processing network, it's like modifying a 747 engine while the plane is in the air: The margin of error is zero. An upgrade of this scope is only possible with the full collaboration of Visa's member banks.
VisaNet is upgraded twice per year - in April and October. Each release entails a nine-month process of fielding requests for new services and upgrades from Visa's worldwide regions and months of quality assurance testing. When the initial version of the upgrade is ready, Visa makes a test bed available to its 21,000 global members for fine-tuning and testing before the update goes into production. The October 2004 system upgrade, the largest to date, resulted in 120,000 changed lines of code and the installation of 27 new or enhanced applications. Some 300 engineers in Visa's development centers worked through a 24-hour time period to successfully install the upgrade in Visa's data centers in the U.S., Europe and Asia - all without serious impact to thousands of member banks, millions of merchants and billions of Visa cardholders worldwide.
Scott Thompson, CIO and EVP of Technology Solutions, Inovant (San Francisco), the payments processing arm of Visa