The use of locating arrays is motivated by the use of generating software test suites to locate interaction faults in component-based systems. In this paper, we introduce a new combinatorial configuration, with which a general combinatorial description of $(ar{1},t)$-locating arrays is presented. Based on this characterization, a number of locating arrays by means of SSOA and difference covering arrays with prescribed properties are constructed effectively. As a consequence, upper bounds on the size of locating arrays with small number of factors are then obtained.