SmartNet is a scheduling framework for heterogeneous systems. Preliminary conservative simulation results for one of the optimization criteria, show a 1.21 improvement over Load Balancing and a 25.9 improvement over Limited Best Assignment, the two policies that evolved from homogeneous environments. SmartNet achieves these improvements through the implementation of several innovations. It recognizes and capitalizes on the inherent heterogeneity of computers in today's distributed environments; it recognizes and accounts for the underlying non-determinism of the distributed environment; it implements an original partitioning approach, making runtime prediction more accurate and useful; it effectively schedules based on all shared resource usage, including network characteristics; and it uses statistical and filtering techniques, making a greater amount of prediction information available to the scheduling engine. In this paper, the issues associated with automatically managing a heterogeneous environment are reviewed, SmartNet's architecture and implementation are described, and performance data is summarized.