About the Mail Study
The United States Postal Service (USPS) hired IBM to conduct independent studies that measure USPS mail delivery performance from the customer's point of view. These studies are managed by IBM as part of the Transit-Time Measurement System (TTMS). IBM maintains a panel of independent contractors, known as Droppers, who drop test mail in USPS collection boxes. The test mail is then delivered to a panel of volunteer recipients who report when it is delivered. The data collected by IBM is reported to the Postal Service so that they may diagnose issues and improve service.
If you would like to view the performance results that IBM provides to the Postal Service each quarter, simply visit USPS Service Performance Page. IBM provides results for all of the mail classes listed under Mailing Services Measurement Results.