Reimagining Control Systems: Modularization as the Key Driver

Fundamentals, influencing factors, and challenges

To counteract technical debt accumulated over decades, the lack of further development, and well-known vendor lock-in, transport companies are rightly considering a modular control system based on the principles and ideas of the Internet of Mobility.

However, it is not that simple. Even at the project’s earliest stages, many fundamental questions remain: How is the current system structured? What interfaces exist? And what exactly should be defined as a "control system"?

At the same time, strategic and technological aspects become more important. What does a future-proof modular architecture look like? How will data be handled? Does the system fit the long-term ICT strategy – and does the company have the necessary expertise and financial resources available?

Issues such as cybersecurity, interoperability, future functional enhancements, and standards must also be considered early on.

But before these topics are discussed, a central question must be asked: What should the control system do in the future – and for whom?

After all, the focus of every strategic decision is not the system itself but the end user:our passenger. Every technical or organizational decision must be measured by its usefulness. A sustainable control system strategy must therefore be considered across multiple dimensions: customer orientation, technical feasibility, and economic viability.

A control system is not an end in itself – it is a central control instrument for operational management in a transport company. Its design, further development, or realignment must therefore always be based on three fundamental objectives:

1 - Customer benefit and user orientation

In the complex system landscape of a modern transport company, the control system primarily acts as a back-end system from the customer's perspective. Nevertheless, as the central control instrument for operational activities it is crucial: it influences several services and systems that interact directly with customers and provide them with essential data. It therefore contributes significantly to the quality of digital, customer-oriented services.

2 - Technical and operational feasibility

Technical feasibility describes the functional and architectural capabilities of a control system – i.e., the technological foundations and prerequisites such as system architecture, interfaces, scalability, availability, data collection and processing, communication and location technologies, and security.

Operational feasibility refers to how these technical functions in day-to-day operations of a transport company: how these capabilities are applied to control and optimize operational processes and create added value for passengers and employees. In short, it is about mapping use cases and operational processes reliably.

3 - Economic efficiency and resource availability

This dimension covers the financial and economic assessment of a control system across its life cycle. Beyond investment and operating costs, medium to long-term expenses and financial risks must also be considered, including:

• Personnel costs for operation, maintenance, servicing, and support
• Costs for maintenance and support contracts and for further development
• Operating costs for hosting, infrastructure, monitoring, and backups
• Implementation and migration costs for project management, data migration, testing, and quality assurance
• Financial risks such as downtime, provisions for system replacement, technology changes, and regulatory adjustments

If one of these three dimensions is permanently neglected, pressure to change will inevitably arise, whether due to dissatisfied passengers, outdated technology, or rising operating costs.

Examples include:

• New mobility offerings, such as on-demand transport or sharing services, that cannot be integrated into the existing system landscape
• Outdated system architectures that no longer meet today's requirements for cybersecurity, scalability, or interoperability
• Increasingly costly system operation, for example due to expiring support contracts, proprietary technologies, or rising license fees

A future control system strategy must therefore balance these three objectives to create a sustainable and robust system landscape for public transport.

Once the strategic target vision is defined— the balance between customer benefit, feasibility, and economic viability — the next question is which factors will influence the future control system.

In the following chapter, we take a structured look at the four central requirement dimensions that shape every control system.

The decision to implement a control system is not purely a technical project – it is a strategic process that profoundly affects the organization, operations, and value creation of a transport company. For such a transformation to succeed, the future control system must meet a range of influencing factors. These can be divided into four requirement dimensions:

Together, these dimensions form the framework within which the future control system operates. They influence technical, organizational, and strategic design, as well as operational processes, interfaces, and partner relationships.

It is important that the requirements do not act in isolation, but interact closely with each other – for example, when new operational processes require functional enhancements or regulatory requirements influence the system architecture.

The challenges described in the next section are directly related to these requirements. While the influencing factors outline the target framework, the challenges describe the hurdles that must be overcome. The influencing factors are not a final list but rather a general overview that must be considered individually for each transport company.

The influencing factors described define the framework and objectives for a future control system – they show what needs to be achieved.

However, there are numerous hurdles to overcome in practice. Often there is a gap between strategic aspirations and operational reality.

In the following chapter, we highlight the key challenges transport companies face when developing and introducing a modular control system.

Challenge 1: Distribution of roles and responsibilities – The transport company in its new role as system integrator

The introduction of a modular control system shifts the traditional distribution of roles: the transport company increasingly becomes the system integrator and central coordinator between suppliers, system components, and operational requirements. This responsibility covers overall functionality, system integration, communications infrastructure, IT security, maintenance, support, and further development, placing high demands on organization, processes, and interface management.

• Key question: Is the transport company ready and able to take on this new role in terms of organization, personnel, and technology?

Challenge 2: Organizational capacity and personnel structure

The new role raises the question of available expertise and skills. Many transport companies currently lack the specialist personnel and appropriate structures to operate a modular system independently. Building internal skills is time-consuming and requires a long-term personnel strategy. Demographic factors (e.g., upcoming retirements) are additional obstacles. Success often still depends on the commitment of individual key personnel.

• Key question: Do we have the necessary personnel or a personnel strategy and structure to implement a modular control system and operate and develop it in the long term?

Challenge 3: Procurement strategy & market availability

The market for fully modularized control systems with asynchronous communication and multiple software suppliers is still immature in the DACH region. Procurement is therefore complex: it requires substantial architectural preparatory work to clearly define system boundaries (e.g., central, stationary, mobile), interfaces, communication channels, and responsibilities for operation, maintenance, support, and further development.

Additionally, setting up an appropriate procurement process—including legal, technical, and strategic framework conditions — is a major challenge. The chronological and technical sequence of procurement steps must also be carefully coordinated to avoid integration problems later.

• Key question: Can we structure a modular procurement project that is architecturally sound, legally viable, and aligned with market conditions?

Challenge 4: Migration and transition phase

As with any introduction of a new, complex system, the migration phase is a critical success factor for modular control systems. Many transport companies underestimate the complexity of this phase.

In a modular approach, responsibility for migration planning and implementation lies with the system integrator. If the transport company assumes this role, it bears full responsibility for the smooth interaction of new and existing system components. This includes not only technical aspects, but also operational, safety-related, and organizational aspects.

• Key question: Do we have the capabilities and the will to develop a coordinated, viable migration strategy that accounts for technical feasibility, operational requirements, and timing?

Challenge 5: Standardization & interface diversity

There is currently no comprehensive, consistently implemented standard for the modularization of a control system or for communication between central, mobile, and stationary components. Although initial approaches are available — such as ITxPT for vehicle architecture and VDV 435 as a comprehensive orientation framework — these are mostly still in development, not finalized, or are only used selectively.

Proprietary interfaces, such as the MPI interface from CN Mobility, show the market is in flux, and not yet standardized.

Transport operators must actively engage with existing and developing standards, make independent decisions about their use, and be prepared to perform pioneering technical work in several areas. This includes selection and application of standards, integration, documentation, and continuous development during ongoing operations.

• Key question: Are we prepared to actively use current standards, evaluate them critically, and, if necessary, supplement and further develop them ourselves?

Challenge 6: Functional requirements & process mapping

A control system must reliably support a transport company’s operational processes. In a modular system landscape, this becomes more challenging: functional requirements must be implemented consistently across multiple, often independent components and providers. This requires a clear understanding of functional relationships during tendering and operations. The transport company must define requirements precisely, assign responsibilities, and ensure that implementation works both technically and operationally.

• Key question: How do we ensure functional requirements are implemented consistently and mapped reliably in a distributed system architecture?

Challenge 7: Strategic orientation & target vision of the control system

The introduction of a modular control system is not merely a technical project – it is a strategic change that affects the organizational, technological, and cultural orientation of a transport company. For success, this initiative must be clearly anchored within the overall corporate strategy and backed by a coordinated target architecture.

The transport company must clarify their strategic direction: Which functions and technologies should be modularized? What role do data, open interfaces, and interoperable platforms play? How does the control system fit the long-term ICT strategy, security architecture, and future market roles (e.g., as an intermodal platform provider)? And what priority does the project have internally?

A missing or uncoordinated target vision quickly leads to isolated individual initiatives without sustainable system benefits. Conversely, a clear vision can drive innovation, cooperation, and market differentiation.

• Key question: Is our control system strategy long-term, clearly prioritized, and backed by a company-wide target vision that effectively supports modularization?

Challenge 8: External requirements & regulatory framework

When introducing a modular control system, external factors such as legal requirements, technical guidelines, and market trends must be considered. Regulatory requirements in data protection, information security, and passenger information are constantly evolving — as are expectations for digital connectivity, data provision, and interoperable system landscapes.

Transport operators must analyze at an early stage which requirements will apply in coming years, which security guidelines must be implemented, and which central systems, data platforms, or official infrastructures must be integrated.

A modular system approach must be technically future-proof and comply with regulatory requirements.

• Key question: Can we identify future regulatory requirements, security guidelines, and market obligations early and integrate them into our system architecture?

Challenge 9: Public impact & market influence

A large-scale control system project inevitably attracts media and industry attention, especially when pursuing an innovative, modular approach. Even early phases, such as requests for information, market consultations, or discussions with other transport companies, can draw public response.

Such a project has both internal and market-shaping dimensions. Managing communication, stakeholder expectations, and public positioning requires a conscious strategy. Transport companies should decide early what messages to convey, how transparent to be, and whether the project should serve as a market example.

• Key question: Are we aware of the public and industry-wide response – and do we have a communication strategy to actively shape the market impact of our control system project?

Challenge 10: Clear project scope & system demarcation

Many transport companies’ system landscapes are highly heterogeneous. Although the control system can be broadly divided into central, stationary, and mobile components, specific demarcations are often blurred. In the mobile sector, some independent modularization approaches already exist — through service-oriented architectures or asynchronous communication via data brokers.

Additionally, numerous standardized and proprietary interfaces connect planning, information, ticketing, or vehicle dispatching systems. This diversity makes it difficult to define a clear separation between the core control system and adjacent subsystems.

Without a clear project definition, modular redesign projects can get lost in unclear responsibilities, technical redundancies, or uncontrolled scope creep. Precisely defining what is to be modularized, which components are affected, and how they will integrate into a target architecture is therefore essential for the success of the project.

• Key question: Do we have a clear, coordinated understanding of which part of our current system landscape belongs to the control system — and what its modularization should look like in interaction with surrounding systems and architectures?

Transport companies considering the further development of their control system should first examine the strategic cornerstones, influencing factors, and challenges outlined above and apply them specifically to their own organization and system landscape.

The influencing factors and challenges are intentionally generic and must be evaluated and weighted individually for each company. Experience shows that, in the course of an in-depth examination, further specific topics will emerge that must be tailored to the particularities of the respective company, its organizational structure, IT landscape, and operational processes.

It is important to note that there is no single right way to implement a modular control system.

Different models can be effective – from complete in-house responsibility to targeted outsourcing to a provider. For example, a lack of internal expertise can be offset by temporarily procuring external expertise or by engaging a system integrator (service). Gradual modularization or targeted partial modularization of individual components can also be appropriate. In some cases, purchasing the entire control system — including peripheral systems — from a single provider may be the right solution.

The decisive factor is not the degree of modularization, but the sound reasoning behind the chosen path. A modular control system is not an end in itself or merely a trend decision. It must reflect a well-considered strategy based on an honest assessment of the company's requirements, resources, framework conditions, and objectives.

Ultimately, every decision should support and create a balance between the three cornerstones. This is the only way to build a future-proof system that meets the company’s specific needs rather than following a technological buzzword.

Where does your company currently stand on the path to modularization?

Share your experiences, insights, or open questions — feel free to exchange ideas with other transport companies.

What does your control system strategy for the future look like?

Share your decisions and strategies and let's review together whether this is the right path for your transport company.

What challenges do you face in your system landscape?

Discuss with us how you define the term "control system" today – and which components you consider to be part of it.

Would you like to delve deeper?

We would be happy to assist you in strategically assessing your current situation, developing a target vision, or supporting system architecture work with our wide range of technical experts and system architects.

Together, we will find solutions to the challenges described. With numerous reference projects throughout Switzerland, we are your reliable partner – from developing sustainable control system strategies to the concrete implementation of technological innovations.

Whether strategic issues in transport companies, technical challenges relating to modern IT architectures, or procurement support: we combine in-depth industry knowledge with technological excellence and our own products.

In addition to our market knowledge of artificial intelligence, cloud and platform technologies, microservice architectures, and cybersecurity, our expertise extends to IoT and edge computing solutions.

Our portfolio also includes a purpose-built data platform that can serve as a central component (transport data platform) for the control system architecture of the future. Combined with our domain expertise, we support transport companies in taking the next step – whether through technical consulting, adapting our data platform to needs, or implementing tools such as ServiceNow for process digitalization.

We are also happy to assist you with specific questions – for example, on the use of AI in public transport, the design of modern system landscapes, or our data platform. Feel free to contact us!