In this study, a Theory of Constraints (TOC)-based method was developed to enhance the efficiency of business processes. Whereas the TOC has been employed in manufacturing processes, the present paper shows that it can be effective also for Business Process Management (BPM). In order to apply the TOC to business processes, a Drum-Buffer-Rope (DBR) scheduling method for a Business Process Management System (BPMS) was developed. A procedure by which business process efficiency can be improved using these concepts is presented. To validate our approach, a series of simulations of a real banking process was conducted, on the basis of which the applicability of the proposed method was analyzed. Based on the analysis results, we show that the TOC-based method can improve business process efficiency, particularly under heavy workloads with limited resources. And we suggest, accordingly, several guidelines that can be followed for the efficient management of business processes.