AbstractOver the last decade, much attention has been given to the development of automated mail processing systems for postal operations. Optical character readers and bar-code sorters have begun to augment the mechanized equipment in use since the mid-1960s. Current automation programmes are aimed at minimizing the growth in labour costs which, at $30.5 billion in the United States, accounted for 83% of the U.S. Postal Service's operating budget in 1988. In this paper, a SLAM II simulation model is developed to assist postal managers in evaluating and implementing new technologies at general mail facilities (GMFs). The Northern Virginia Area GMF, located just outside Washington, D.C., serves as the baseline. Results are presented for a proposed design embodying a variety of new concepts and equipment, including carrier route sequencing. Annual savings of over $6 billion are estimated to accompany nation-wide implementation of this design. Alternative scenarios involving changes in mail volume and address quality are also investigated. The analysis demonstrates the system's sensitivity to relatively modest increases in traffic, and points up the need for integrative long-range planning.