More suppliers, of course, are now getting paid on time. According to Cassera, on-time payments are way up, more than 95% today, versus just 15% before Sloan-Kettering started using Xign. The other 5%, she says, are invoices that require additional time for approval.

Instead of Sloan-Kettering cutting checks, most of the payments are handled through an automated clearinghouse. About 85% of invoices coming in to Sloan-Kettering are submitted electronically, most via Xign. The majority of the organization's 1,000 top suppliers use the online service to submit invoices and receive payments. "Our bigger suppliers are all doing Xign with us," Cassera says.

She admits that converting the remaining large suppliers may be more difficult. One reason is that some companies simply resist changing their processes and learning to use a new technology to bill their customers. "You have a lot of proprietary suppliers out there," Cassera says, referring to companies that provide a product or service that isn't easily replicated by someone else. "You can't tell someone who provides a specific patient-care item to take a hike."

Another reason some suppliers resist converting to electronic payments is that they don't want to share their banking information. "You are always going to have the one-off vendors who will not give you their banking information, and who still want a paper check," Cassera says. Nevertheless, she figures to get even more of Sloan-Kettering's supplier base on board over time: "Our goal is to get 90% of our invoices processed this way by the end of 2007."