Ahmad Jamil
This chapter introduces the concept of the digital twin at a foundational level to address common ambiguities and misconceptions surrounding the term. It aims to help readers not only understand what a digital twin is, but also how to systematically approach its development. The focus is on establishing a clear, technology-agnostic framework that guides the creation of effective digital twins. By prioritizing conceptual understanding over specific tools or platforms, this chapter provides core guidelines that can be applied across various domains. These principles are then demonstrated through a case study involving the development of a digital twin for a laboratory-scale packed-bed thermal energy storage system. The case study illustrates how the proposed guidelines can be practically implemented, and maps them to a more complex, technology-specific digital twin developed in the original study – highlighting the adaptability and robustness of the framework.