WASHINGTON — The Postal Service is replacing dozens of unconnected human resources systems nationwide with one that will allow its 700,000 employees to make benefit and payroll changes on a single Internet site.

The PostalPEOPLE system, using software from German company SAP AG, will be the largest in the world when finished, said Andy Malay, a vice president at SAP America in Washington. It is being rolled out in phases to replace a hodgepodge of more than 70 systems, used by 3,800 HR managers across the United States.

The government has a mandate to move away from paper-based systems and is likely to continue transitioning to Web-based HR systems for employees who often work nontraditional hours around the world. Software from SAP rival Oracle Corp., via its acquisition of PeopleSoft Inc., is being used for a Department of Defense system, which is scheduled to be available for about 3 million military service members starting in 2008.

Similar to Web-based human-resources programs that are increasingly common in private companies, PostalPEOPLE allows workers to access benefits, compensation, and retirement and separation files and other HR-related information from any computer with an Internet connection.

Some services previously were available online, but through numerous outdated systems that required visiting different Web sites with different passwords, while other transactions required an in-person meeting to fill out paper forms, said David Partenheimer, a Postal Service spokesman.

Both employees and managers can complete HR activities on the system. Identification and pin numbers will be required to gain access and additional security is in place to prevent identification theft, Partenheimer said. Sensitive payroll data and other information will be stored on a mainframe computer and not be available for download on laptops and other personal computers.

"They're certainly creating a treasure trove of data, but I'm sure they know that," said Donald Harris, founder of HR Privacy Solutions Ltd., a New York consulting firm. He added that the Postal Service's use of role-based access based on the employee's job, as well as identification and PIN numbers is "fairly routine," and that the numeric sequences should be longer than four digits and kept private.

Not allowing data to be downloaded from the mainframe to PCs is innovative and makes the information less transferable, but Harris said additional steps should be taken including "automatic time-outs" if someone is idle while logged into the mainframe for certain period of time.