DTReq4.0: a catalog of digital twin requirements for Industry 4.0

Digital twins (DT) have been applied across different product life cycle stages, such as design and operation, and have been crucial in advancing various application domains, including Industry 4.0. For DT development, identifying their requirements is essential to ensure that the projects meet expectations and mainly describe the digital model containing the characteristics and behavior of physical twins. These requirements could also enable cost estimation, interoperability between systems, and communication with stakeholders. However, existing studies on DT requirements are fragmented and lack a comprehensive understanding of what these requirements are and how they could be structured and specified. Additionally, defining such requirements is challenging for engineers and developers. This paper presents DTReq4.0, a requirements catalog that describes the key requirements of DT, particularly those for Industry 4.0. For this, we first systematically selected studies that address DT requirements through a literature review. We then collected and analyzed these requirements using a coding technique and identified 59 essential requirements that we organized into 16 categories, thus putting together the essential requirements for DT. Following this, we designed DTReq4.0 that contains these categories and requirements and associates them with the three key components that usually constitute DT (information model, data communication, and data processing). To evaluate the feasibility of the catalog, we conducted a proof of concept (PoC) using a representative use case and an interview with a DT expert. We also provide perspectives for future research. We believe different industries intending to develop DT could benefit from this catalog by supporting them in identifying DT requirements.