Abstract: In this paper the State Variable Star Algoritnm(SVSALG) is briefly introduced. The identification of equivalent faults in logic networks is treated with the algorithm.It is shown that SVSALG is an efficient means to analyse fault equivalence. Based on the algorithm, the conception on a particular type of equivalence fault classes, the strongly connectivé equivalence fault class, is presented. The properties of the. equivalence class and its importance for multiple fault analysis are discussed in detail.