National CCS DRACAS: Project Progress and Key Outputs

Collaboration is essential

The National CCS DRACAS affects the whole industry, so industry-wide collaboration is essential to develop and implement it.

Different organisations have a wide range of experiences and perspectives. Working with them enables us to identify work and dependencies that are critical to success. It also reveals the ways in which different workstreams interact with each other.

The roadmap established where multiple workstreams need to collaborate. A workstream may start by working on ‘its own’ tasks, but it may also need to collaborate with another workstream later on.

Making the National CCS DRACAS a reality is a very large, long-term project involving many stakeholders over several years. Its success depends on having a structured process. To ensure that the system works for everyone, collaborating with industry in that process is key.

Our work with industry so far has produced important outputs in a structured sequence. These are:

System model

To define and understand the National CCS DRACAS, RSSB used a Model Based Systems Engineering (MBSE) approach to set out exemplary National CCS DRACAS processes.

The system model brings National CCS DRACAS processes into alignment, such that all interested and affected organisations can develop towards the same end goal. It sets out a common vision and takes a systematic approach to detailing the interactions required between organisations. This makes the future development and implementation of the National CCS DRACAS easier.

Concept of Operations

The system model is summarised in the RSSB Concept of Operations (ConOps) for the National CCS DRACAS. It sets out, at a higher level, what the National CCS DRACAS needs to achieve. It details the proposed national processes, the roles required to support those processes, and how organisations need to work together.

Rail Industry Standard RIS-0707-CCS Issue 2

Based on the contents of the system model and ConOps, RSSB updated Rail Industry Standard RIS-0707-CCS Management of Control Command and Signalling (CCS) Subsystem Failures, Faults and Defects. The updated standard sets out the requirements for information sharing between organisations on failures of CCS subsystems. It also includes the requirements on the National CCS DRACAS itself. Guidance is included for each requirement that explains how that requirement might change once the National CCS DRACAS is implemented.

The revised standard, Issue 2, was published in September 2023.

In developing the standard, RSSB set out:

• A series of definitions related to DRACAS, failures, faults, defects, corrective actions and preventative actions. This included guidance on linking human performance factors to technical investigations.
  View further information on Unwanted events, defects and counteraction's page.
• Common failure symptoms and risk classifications for CCS systems, including the new table for ETCS. The standard also features guidance on how to prioritise CCS failure investigations by creating a hazard index (using risk potential rather than delay minutes).
  View further information on Investigating CCS failures' page.

Roadmap

After the vital theoretical work for the National CCS DRACAS, industry needed to discuss and agree the next steps. The National CCS DRACAs roadmap was produced after workshops with industry. We involved nearly 50 stakeholders in the work on the roadmap. Together we agreed what needed to be done and the order in which different projects needed to be carried out.