1. A method of early high level net based analysis of simultaneous switching in circuit designl comprising the steps of: associating a characteristic triangle with each driver application configuration, where a driver application configuration is a driver in a specific usage environment, including a receiver, terminator and package wiring characteristics, said characteristic triangle being an approximate model of a driver's current flow over a short time during its transient switching stage and derived from a switching curve of a driver type; summing magnitudes of all triangles at each instant or step in time and graphically representing the simultaneous switching activity within a defined design boundary; and using the graphical representation of the simultaneous switching activity to determine whether switching activity of the present design exceeds acceptable limits.