Hydrogen utility consumption minimization is one of the key strategies for reducing refinery operating costs. Process integration techniques have been widely accepted as an effective tool for reducing hydrogen consumption. To date, various pinch based conceptual methods have been developed. Applying the pinch analysis is simpler than solving the mathematical model. However, the relationship between the pinch simplification and the mathematical model has seldom been addressed. In addition, existing pinch analysis paid little attention to the rare but realistic cases of threshold problem. In this article, the original mathematical model is associated with the pinch concept by proving simplified equivalent formulations. A mathematically rigorous systematic targeting approach is then obtained by mathematical deduction. The proposed method combines pinch insight with a rigorous mathematical optimization technique. The proposed method addresses both threshold and pinch problems, and initially the analysis is restricted to systems with no purification unit. (C) 2010 Elsevier Ltd. All rights reserved.