1. A method for analyzing the capacity of an application executing on a parallel processing system and expressed as a graph of vertices, comprising the steps of: a) creating a description of the sizes of data records throughout the graph; b) creating a performance description of each vertex in the graph; c) determining an execution time for each vertex in the graph; d) determining counts of data records assigned to corresponding vertices in the graph; and e) creating a description of the total execution time and performance of the system based on the determined execution time and counts of data records.