# The Role of Multi-Agent Systems in Realizing Asset Administration Shell Type 3
## 2 Background
### Asset Administration Shell  
The so-called I4.0 component, introduced by the RAMI4.0, encompasses an asset and its corresponding AAS. The AAS is defined as a standardized digital representation of an asset, encapsulating all relevant asset information throughout its lifecycle [10]. As illustrated in Figure 1 (right), the AAS has a well-defined structure comprising a collection of submodels, where each submodel can be viewed as a modular building block that encapsulates specific information about the asset, such as identification, capabilities, technical data, and operational data.  
Today, the Industrial Digital Twin Association (IDTA) is responsible for standardizing the AAS, providing a set of specifications and submodel templates to support AAS implementations. For instance, _Part 1: Metamodel_ specification [10] describes a technology-neutral AAS information metamodel, presenting the main classes and their relationships to develop AASs. On the other hand, _Part 2: Application Programming Interfaces_ specification [14] defines APIs for enabling access to the information provided by an AAS. Additionally, submodel templates guide the creation of submodels based on predefined structures. For instance, the _Asset Interfaces Description_[15] submodel template specifies an information model and a common representation for describing the interfaces of an asset service or asset-related service.  
Figure 1: AAS overview (**bottom**), AAS types (**top**), and AAS basic structure (**right**).  
Additionally, as shown in Figure 1 (top) and described in Table 1, AASs can be classified according to their interaction pattern to exchange information and degree of autonomy to make decisions [3].  
The central idea behind the concept is that each asset in the industry is represented by its own AAS, transforming it into an 14.0 component. In this context, since all AASs adhere to a common standardized structure and expose I4.0-compliant interfaces, they can seamlessly provide and exchange information throughout the asset's entire lifecycle. This standardized communication enables interoperability and real-time data sharing among heterogeneous assets, regardless of the manufacturer or domain. Consequently, through their AAS, assets are expected to collaborate autonomously, coordinate processes, and support decentralized decision-making within industrial environments. However, this vision of autonomous, intelligent, and collaborative behavior is more closely aligned with AAS Type 3, which remains relatively underexplored compared to the other types, namely AAS Type 1 and Type 2, and currently lacks dedicated specifications and comprehensive implementation guidelines.  
Finally, a recurring question in the community concerns the relationship between the AAS and the Digital Twin (DT) since both are defined as digital representations of assets. Given the growing popularity of both concepts, several studies [16; 17; 18] have investigated their interrelation and distinctions. These studies reveal that the relationship between AAS and DT is subject to varying interpretations. Some sources treat the AAS as a synonym for or an implementation approach to DTs, while others regard it as a foundational information model that enables the creation and interoperability of DTs. Moreover, the suitability of AAS as a representation of a DT is seen to increase along the AAS types, from Type 1 to Type 3. In particular, AAS Type 3 is considered to have the strongest alignment with the DT concept, potentially serving as a near-complete implementation technology for DT, as discussed in [18].  
It is important to emphasize that this work does not aim to engage in broader conceptual debates. Therefore, it specifically focuses on the AAS, and in particular AAS Type 3, as a standardized framework for advancing digitization and interoperability in I4.0 environments, aligned with the principles initially proposed by Plattform Industrie 4.0 and IDTA.