Internally, many source code analysis tools make use of graphs. For example, one of the oldest and most widely used internal graphs is the control-flow graph developed for use within a compiler. Work on compilation has also led to the development of the call graph, the procedure dependence graph (PDG), and the static-single assignment (SSA) graph. Compilers are not the only source-code analysis tools to use internal graphs. A variety of software engineering tools incorporate a variety of different graphs. A study of techniques that improve graph-based program analysis is presented. Several different techniques are considered, including forming strongly-connected components, topological sorting, and removing transitive edges. Graph reachability, a pervasive graph analysis operation, is used as a representative graph analysis operation in the study. Data collected from a test bed of just over 1,000,000 lines of code is presented. This data illustrates the impact on computation time of the improvement techniques. Overall, the combination of all techniques produces a 71% reduction in run-time (and 64% reduction in memory usage). In other words, they increase the size of the problem that can be effectively handled by factor of over three times.