Rail Systems Integration is a Contact Sport

Negotiating the many moving parts of the UK rail system is more complex than many defence projects, says Kevin Gedge, SYSTRA’s UK & Ireland systems engineering lead.

Systems engineering has traditionally been associated with ‘complex industries’ such as aerospace or defence. Its purpose is to somehow weave together a myriad of components and technologies, together with human players, to create the optimum output.

With the ever-increasing complexity of the UK rail system, systems thinking is also a necessity for modern rail projects. Ensuring track, train and timetable are seamlessly operating together is paramount. This has led me to the proposition – could the railway be more complex than those other industries?

Just mapping out the network of stakeholders is a task in itself, encompassing government departments, the infrastructure owner, train operators, rolling stock owners, manufacturers, suppliers and many others integral to the operation of the whole rail system. Add onto this that our existing rail system has evolved organically over centuries; and that all upgrades must be constructed, tested and entered into operation with limited impact to existing services for passengers and freight. Finally, and for good measure, throw in rapidly evolving digital tools, customer expectations, an urgent need to decarbonise transport to reach net zero and the diverse needs of members of the public who interact with the railway system.

Without an ability to balance the various and often opposing perspectives, we are expecting our decision makers to fly blind or, at least, with a heavily restricted view. It is hardly surprising, then, that the jigsaw pieces of some rail projects don’t always fit together and so run into problems. Managing uncertainty, differing needs in terms of urgent and important works, project lifecycle cost vs whole lifecycle cost and the need to cope with change are often contributory factors.

Applying a systems approach to big, complex infrastructure upgrades is vital because it can better predict and demonstrate the wide-ranging impacts of change and smooth the transition to operation – which inevitably reach beyond the scope of the project in question to include political, reputational, and environmental impacts. Where change is imposed, a systems-led approach is one way to manage and mitigate any far-reaching detrimental impacts.

Beginning at the end

Often rail projects tend to start at infrastructure level: building or extending railway lines, widening tunnels, and adding bridges. A systems approach takes a step back to look at what outcomes are ultimately needed and then works back from there.

For instance, Northern Powerhouse Rail from the start, set itself whole industry level performance-based outcomes such as a specifying a desired journey time between Manchester and Leeds. The goal was to find the optimum solution for the money available, balancing how this can be achieved through rolling stock and infrastructure capability as well as timetable design in a top-down approach without being constrained by thinking first about any single element.

There are constraints, of course, linked to existing railway infrastructure and services. One of the biggest challenges for any UK rail project is that information related to existing performance is often not at the granularity to allow effective decision making.

One of the first tasks for any systems integration team is to understand the existing system and its interfaces together with the stakeholders involved. Going through this process helps to unearth constraints or issues within the existing system that would impact on planned projects or interventions. Furthermore, it often identifies limiting factors that sit outside the boundary of the system of interest but crucial to meeting commitments.

As with other sectors, digital twins are proving useful for working out how new and old will work together. Additions to a system or interventions to existing systems can be played out virtually to test different options and look at how future scenarios could be accommodated. However, effectiveness of the model is again limited, modelling train delays from outside of the system boundary or reliability of assets not within the project footprint adds complexity and begs the question when do you stop? Such additional detail will increase the time a model takes to run, which in turn affects the agility of using modelling and simulation to inform design.

SYSTRA’s work on high speed rail projects including Northern Powerhouse Rail enables projects to benefit from a systems led approach to delivery.

There is also a danger that systems engineering for rail projects gets stuck at infrastructure asset level too, homing in on elements such as signalling, tracks, stations, and civil engineering structures and how they fit together. However, that view misses out on a crucial layer of integration which must be managed for a rail project to be successful.

Above the infrastructure integration layer sits industry level integration, this involves entities such as the Department for Transport, franchise operators rolling stock owners and maintainers coming together with the infrastructure owner. With each having their own stakeholders and organisational objectives, integration involves getting them to sign up to common goals to deliver an outcome such as a significantly improved passenger timetable. But in doing so, several incremental changes over a phased migration from current to future end state is necessary to limit impact to passengers.

Experience on rail projects globally has shown that phased migrations deliver better long-term approaches. But providing a safe, operable, and performing railway during the transformation journey is not easy. The interdependencies, interplays, and knock-on impact of delay to one element of the migration is complex and requires openness by all parties involved to generate and maintain an accurate and trusted system migration plan.


Mark Wild, former Crossrail CEO, has been famously quoted as describing ‘systems integration’ as “almost a contact sport”, which is incredibly apt. There can be some very robust discussions and encounters as players at industry level seek to reach a consensus on what the project outcomes should be.

A systems integrator must sit down with the different parties, understand all perspectives, and often act as a technical translator to generate a shared vision defined by the requirements for the project. It is a sometimes painful, but a necessary process. Without it, there will be far more pain for the project to deal with further down the line from diverging expectations, scope gaps or previously unidentified constraints.

Perhaps the most painful change that the rail sector faces is the need for a completely different mindset in delivery. A systems approach rejects the idea of a heroic project leader who saves the day at the 11th hour, instead favouring a methodical ‘mission control’ structure which requires power to be devolved to a series of teams who have clarity of their remit and the competence to carry out their part of the works.

This approach, as already applied in similar industries, should also lead to better and more timely decision-making, with empowered teams having the flexibility to act quickly when needed. Too often, decisions are not made or delayed because of limited information or they are constrained by programme and budget milestones which ultimately may compromise the final project quality and performance.

One of the perceived downsides to a systems-led approach could be that more time will be spent in the earlier phases of a project. However, experience has shown that taking more time upfront to understand the problem and identify constraints, boundaries and interfaces will lead to less time overall and reduced risk of rework and cost in the delivery phase. It will be exciting to see how this plays out on rail projects such as Northern Powerhouse Rail and the upgrade to HS1 that are actively applying a systems-led approach.

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