## 4 Proof of Concept Implementation
### Comparison Mechanism
For these reasons, we will continue our research in future works to enhance the consistency management process by creating a library of label components that can be shared between different designers to enable fast verification of correspondences between models and to reduce the number of iteration of the comparison process. Also, a mechanism for solving inconsistencies should be implemented using transformation rules as proposed for software engineering in [43]. ## 7 Conclusions

In the context of MBE, the development of mechatronic systems presents the particular challenge of the consistency between different models arising from the collaboration of multiple domains. Generally, different designers study the system from different viewpoints. Consequently, inconsistencies may occur in the course of the development process due to the existence of different interconnections between different models of a mechatronic system. The main contribution of this paper is to ensure the consistent development of mechatronic systems. To reach this objective, we have presented a model synchronization methodology composed of three phases. The first phase allows representing domain-specific models in a common formalism based on graphs. These abstractions are used in the second phase to perform comparisons based on a subgraph isomorphism algorithm allowing the identification of differences and inconsistencies between the various models. The comparison process is an iterative process where the project manager is consulted to propose alternatives to solve the detected inconsistencies. The final phase is based on the comparison results to update the original models applying a model transformation mechanism. The technical viability of the methodology is shown using an EMA case study. Although being a bench-scale, academic case study, the EMA is complex enough to demonstrate an excerpt of the challenges that arise during engineering of mechatronic systems. It illustrates that there are many interconnections between the considered viewpoints. The EMA system proves that our proof of concept implementation allows checking consistency and detected inconsistencies at an early stage of the design process. The methodology proposed in this work presents many advantages such as ensuring multidisciplinary interactions between multiple designers at an early stage which increase the competitiveness and reduce the development time and cost. It aims to ensure the consistency between domain-specific models and to automate the change propagation during the concretization phase. Furthermore, the methodology allows an exchange between multidisciplinary designers without needing to understand the formalisms of other experts due to the use of a common representational formalism. The developed methodology is not limited to any particular domain and can be provided as a step towards unifying the various domains involved in the process of mechatronic system designs. However, the methodology has some limitations: The model synchronization approach is applied only on structural and hierarchical models. The use of a specific vocabulary for each domain results in iterative cycles needed to apply the comparison process since the interconnected information is captured a priori by a human (i.e., the project manager). Also, the classification and resolution of differences are manual processes that depend on the project manager activities. In future works, we will explore how our method can be extended to support the consistency management of behavioral models. As a first step, we will use behavioral models (e.g., the SysML state machine diagrams and the Altarica GTS model that represent states/events formalism for reliability study). Therefore, we can represent the behavior models using graph representations and implement our techniques to analyze the consistency between behavioral models. This is a preliminary solution to ensure semantic consistency based on the model synchronization approach.