In performance measurement of the firms using tools such as data envelopment analysis (DEA) models, weak efficient units are almost appeared as reference points in the models. To avoid zero weights or equivalently non-zero slacks in DEA assessment, weights restrictions are used frequently. In DEA literature, two-stage procedures are developed to deal with non-zero slacks based on restricting input/output weights in multiplier formulating the CCR DEA model. In this paper, a single-stage approach for efficiency evaluation is developed to ensure zero slacks in target setting and avoid weights dissimilarity. A real case on electricity distribution companies in Iran has been given to demonstrate the applicability of the proposed approach.