In this paper, sliding mode control of inventory management systems is considered. A new method of sliding hyperplane selection for these systems is proposed. The method utilizes the state matrix in the so called Frobenius form in order to simplify the selection process of the sliding variable. In contrast to most conventional approaches, the sliding variables considered in this work can have any relative degree. It is demonstrated that the proposed method ensures the desirable properties of the considered inventory management system. Furthermore, the new method is shown to guarantee a finite time response of the system even though it does not require explicit eigenvalue placement.