How much is enough?
How much SI effort to expend needs to be determined on a case-by-case basis, taking into account the project type, size and complexity. An extreme approach is to not have SI at all. The other extreme is to continually re-analyse and re-define every detail at the risk of delaying progress.
There is however a workable middle ground that can deliver real benefits, practically and effectively by undertaking the right amount of SI and properly balancing it against risks and project outcomes.
Traditional commercial rail projects prioritise delivery cost and timescales, with a focus on using off-the-shelf systems. The role of SI in these cases is less intensive, and it focuses mostly on ensuring compatibility across the different systems interfaces and equipment. Likewise, because the verification and validation of these systems are generally limited to standardised tests, the full Verification and Validation process is scaled down to Testing and Commissioning only.
Recent advances in rail technologies are now driving operators, project sponsors and construction contractors to have an earlier focus on total systems performance and project outcomes. This is largely due to the impact that new technologies have on the performance, reliability and safety-critical functions of the railway – all of which need a carefully planned management approach for their successful integration and implementation. As the complexity of a project increases, particularly across integration of new technologies, a thorough SI approach becomes essential to ensure that the built system will fully meet client expectations and that the railway will perform safely and reliably from day one of operation.
A voice of authority
In the instance of the highly complex projects, it becomes essential to dedicate an experienced team to lead the SI effort as early as possible. An SI Authority – a relatively new concept in the industry – acts to consolidate the business needs and integration requirements, ensuring risks are carefully mitigated at each stage of the project life cycle, and a robust operational railway is delivered.
Using a highly competent team of experienced engineers, railway operators and maintainers, the SI Authority will guide and direct the systems integration activity, provide SI management (including supervision and coordination of delivery), define the end-user requirements, oversee interface management and provide input to longer-term risk mitigation and change management.
The contractual and quasi-contractual relationships that are established for project delivery organisations need to be set up to support SI by allowing for quick decision-making and effective collaboration towards common goals. As experienced in recent light rail transit projects, the problem of uncoordinated contracts has been a major constraint to the implementation of the SI process.
The SI Authority should operate in a 'digital twin' context, where all aspects of the railway throughout its life cycle (from materials and procurement to operations and service) are fully integrated into a live online environment.
Ultimately, for digital technologies to realise their undoubted potential their application needs to be skilfully coordinated by SI Authorities. Doing so will significantly improve the delivery and performance of major rail projects around the world.