This chapter presents a framework for modeling the critical functions of the supply chain and developing a simulation-based digital twin for supply chain monitoring and performance management. Digital Twin (DT), as an emerging technology, can be of great value to supply chain design, control, and informed decision-making. It can support end-to-end management of the value stream across supply chain functions (i.e., procurement, production, and distribution). The proposed framework is based on a comprehensive coverage of the supply chain using SIPOC (Suppliers–Inputs–Processes–Outputs–Customers) structure and Value Stream Digital Twinning (VSDT). It expands the scope of conventional factory-level value stream into an overall value chain using Discrete Event Simulation (DES) for supply chain modeling. The simulation serves as a flexible and relatively cheaper platform for supply chain digital twinning while being representative and supportive of timely (e.g., real-time) decision-making. The chapter outlines the supply chain modeling techniques that are essential for transforming the simulation platform from digital shadowing to digital twinning. It also discusses the technology requirements for establishing an effective simulation–physical communication and the potential integration with relevant AI applications for data analytics and machine learning.