The state transition table method of finite state automata theory has been used to automate causality assignment in bond graphs. The state transition table consists of rows for each type of node in the bond graph: E, F, R, C, I, T, G, 0- and 1-junctions, and columns for the various conditions that can occur at the nodes: starting state, effort state, flow state, R state, and R opposite state. The cells of the table describe what action to take, such as assign causality, go to another state or execute a reversal procedure to pick the next starting node when causality has been extended as far as possible along the current path. The method is complete in that it attempts to resolve all causal conflicts. It is more efficient, requires less code, and is more easily maintained than conventional if-then-else programming techniques.