Digital Twin is one of the promising digital technologies being developed at present to support digital transformation and decision making in multiple industries. While the concept of a Digital Twin is nearly 20 years old, it continues to evolve as it expands to new industries and use cases. This has resulted in a continually increasing variety of definitions that threatens to dilute the concept and lead to ineffective implementations of the technology. There is a need for a consolidated and generalized definition, with clearly established characteristics to distinguish what constitutes a Digital Twin and what does not. This paper reviews 46 Digital Twin definitions given in the literature over the past ten years to propose a generalized definition that encompasses the breadth of options available and provides a detailed characterization which includes criteria to distinguish the Digital Twin from other digital technologies. Next, a process and considerations for the implementation of Digital Twins is presented through a case study. Digital Twin future needs and opportunities are also outlined.

Digital Twin是目前正在开发的有前途的数字技术之一，以支持多个行业的数字化转型和决策。尽管“数字孪生”的概念已有近20年的历史，但随着它不断扩展到新的行业和用例，它还在不断发展。这导致各种定义的不断增加，从而有可能稀释该概念并导致该技术的无效实施。需要一个统一的，概括的定义，具有明确确立的特征，以区分什么构成数字孪生，什么不构成数字孪生。本文回顾了过去十年中文献中给出的46种Digital Twin定义，提出了一个笼统的定义，涵盖了可用选项的广度，并提供了详细的表征，其中包括将Digital Twin与其他数字技术区分开的标准。接下来，通过案例研究介绍了实施Digital Twins的过程和注意事项。还概述了Digital Twin的未来需求和机遇。