This is an individual chapter of Theory of Constraints Handbook. The function of this chapter is to describe the present unsustainable compromises companies are injected offered the present highly volatile international supply and production landscape. The chapter introduces a brand-new principle called Actively Synchronized Replenishment (ASR) that gets over the imperfections of standard MRP and ends the requirement for these inadequate and pricey compromises. ASR leverages MRP, DRP, TOC and Lean practices and strategies with innovative and advanced brand-new guidelines for demand driven supply generation and execution to develop unexpected presence and control throughout an enterprise and supply chain. Using ASR can greatly improve the effectiveness and sustainability of Drum-Buffer-Rope and Lean manufacturing applications.