Skip to main content

System architecture and Conceptual Data Model for railway, common data dictionary and global system modelling specifications

Periodic Reporting for period 1 - LINX4RAIL (System architecture and Conceptual Data Model for railway, common data dictionary and global system modelling specifications)

Reporting period: 2019-12-01 to 2020-12-31

The railway sector is currently acting in a fragmented way and in silos corresponding most often to physical or functional subsystems or use cases, and the different owners/managers of the overall infrastructure at regional/national level, without global extensive view or full control of the global system involved by rail operations.

With the progress of digitization, analogue devices based on relays were progressively substituted by digital ones, and it is more and more evident that enabling the communication between already existing digital tools for various subsystems can be beneficial. What is missing is an efficient, automated and standardized way for these integrated and interplaying systems to act as one ecosystem: sharing, integrating, identifying, correlating and exploiting the right data at the right time.

In order to meet these challenges, the objective of LinX4Rail is to develop and promote a common Functional Rail System Architecture for the Rail sector, as requested by EC. It will be supported by a widely adopted Shift2Rail Common Data Model that, with the commitment of the Shift2Rail members, will establish the standard for interactions between legacy and new systems, thus ensuring sustainable interoperability between systems.

The ambition of LinX4Rail is to achieve a comprehensive approach for the CDM, as a models’ federation, global system modelling specification and the strategy for implementation of technological breakthroughs, with the inputs from a communication system perspective. Both the “System of systems” architecture and the S2R-CDM should be open (easily extensible), and free for any usage.

The development of the “Systems of Systems” and S2R-CDM will take advantage as much as possible of existing current initiatives such as Reference CCS Architecture (RCA), TAP/TAF approaches, RTM, EULYNX, railML Ontorail in order to reach a single universally accepted “System of Systems” approach for the entire sector.

The objectives of LINX4RAIL are:
- To build a Common Rail Dictionary, in collaboration with current initiatives,
- To design the S2R-CDM Modelling,
- To proof concept through at least 3 use cases
- To set up the strategy for implementation of technological breakthroughs (including RCA)
- To develop a shared Common architecture vision
During 2020 LinX4Rail run a series of workshops with all rail-relevant stakeholders (project’s partners together with external initiatives and experts) in order to rethink the rail system and to introduce a common vision and build the first version of a rail Functional System Architecture. These workshops allowed to collect knowledge from other sectors, refine iteratively common understanding on the concept of an architecture for the railway system and implementing a structured approach based on use cases. The work returned into shared concepts, definitions and modelling for dictionary, CDM design and development, use case and architecture:

- Functional specifications of the Dictionary have been released.
- In the vue of the creation of a federated rail system model, rules have been agreed with all model stakeholders and preliminary input on CDM for use case developments in WP4 has been established.
- A preliminary definition of a set of indicators has been done to quantify the quality, usability and suitability of the CDM solution to be designed and applied to the identified use cases. Preliminary description of use cases that should make use of CDM has been established.
- The project delivered the “Identification of Common Business Objectives for the existing and future Railway System”, which shows the specific objectives of the stakeholders, helping to understand better their business drivers. First Business impact assessment were done.
- The first high level released of Functional Railway Architecture was done, based on major use cases in rail operation (“transport from A to B” and maintenance”).

The work performed in the project makes use of the ED Program Board and change management process and relies on a deep involvement of the partners, of external experts and external initiatives. The LINX4RAIL’s advisory board met first in December 2020 and aims at providing guidance on the production, in terms of relevance of the approach and scientific coherence, of architecture and system modelling, and on how the results could be applied by railway organizations not involved in the project.
No global approach for a global Railway System Architecture had been undertaken so far. Existing initiatives in the railway sector were mainly relevant to subsystems of somehow limited scope, with no collaboratively formalized agreed sector business objectives existing so far.

A synthesis and lessons learned from other sectors initiatives enabled the main option agreed for the Architecture (three-layer structure, see below). The project set up common basic principles and structure for the sector Railway System Architecture and had wide exchanges with rail sectors, on architectures initiatives and how they affect existing Shift2Rail projects.

As we start from a situation without any system architecture, a dedicated task supports the definition of principles towards the definition of the governance of the system architecture at the European level.
LinX4Rail produced in November 2020 the first preliminary version of the rail System Architecture. The proposed architecture is based on 3 layers: Services, Operations and Resources layers. The 3-layer concept was assessed and developed on two use cases: “running a train from A to B” and “maintenance”.

Parallel to building the System Architecture, the assessment and alignment of some of the currently existing initiatives was carried out in a dedicated task, following a positive assessment based on Change Management process and endorsement of the change subjects by the Executive Director’s Programme Board (EDPB). Furthermore, following the consideration of the subject “Harmonisation of operational rules”, it was decided to write and publish a white paper on harmonizing the operational requirements for ERTMS with no trackside signals. This document results from the work of a group, constituted with LINX4RAIL’s members and experts nominated by IP2 members and ERA. Its purpose is to describe how and in which area operational harmonisation would have the intended impact.

For the CDM workstream, a functional specification of the appropriate ontology was produced from a review of the existing ontology approaches. Based on the Railway Ontology to be developed in the project, the representations in these currently existing models will be put into a coherent framework. From this approach, the target CDM vision was developed. Having in view shorter term implementation in Shift2Rail projects, the concept of a short-term version of the CDM was developed. Agreement was reached in June 2020 to support both Intermediate UML based solution and long-term ontology based solution, therefore the project runs two parallel workstreams. and It will be tested on the above identified project use cases The chosen approach envisages the possibility for CDM users to extend the model to fulfill their use cases if the required entities are not included in the short term CDM. The CDM is then open and adaptable by design to contributions of actors of the railway sector, inside or outside Shift2Rail. A core development team is now in place to carry out the implementation work.
Project logo