Complex Engineered Systems – Theme

As a function of the rise of information technology, the nature of our technology infrastructure is changing. From driving to work, to paying for a cup of coffee, to checking our emails, with almost every action and activity in our lives today we find ourselves now operating within complex systems of technology that are networked together through information technology.

In the Industrial Age, we built individual systems but with the advent of information technology and globalization, a new world of integrated networked systems that span across specific technical domains is emerging. This brings a whole new paradigm to our technology infrastructure challenging our engineering capacity, but understanding how to design and build these complex engineered systems is more important than ever.

When we think of technology we are apt to think of standalone machines and devices, a chair, a car, a television, individual physical systems that perform standardized mechanical functions. However, today our technology infrastructure is evolving fast as we embed computation into all kinds of machines and connect them up to ever larger networks. Previously disparate systems are becoming connected and required to interoperate in performing combined functions – people no longer want “things” that do “things” they want systems the delivery integrated services.

As a function of these changes in our technology infrastructure, we increasingly find ourselves required to design, build and operate ever more complex engineered systems, however, what we mean by the term complex engineered system is still open to definition.

What are Complex Engineered Systems?

This new world of complex engineered systems is qualitatively different from the kind of systems we build during the Industrial Age. Firstly it is about open systems, meaning that they have such a high level of interaction with their environment that their boundary is not well defined. Added to this, they are composed of very many elements. We may be talking about millions, billions or even too many components for us to be able to quantify in any meaningful way. Likewise, it may be very difficult to say which of these components is part of the system and which are not.

These sociotechnical systems are often highly dynamic and loosely coupled, components are leaving and joining, coupling and decoupling from the system in a dynamic fashion. They are deeply interconnected and interdependent with their environment, think about a transport system that is critically interdependent with its energy network and information system.


These systems are highly nonlinear many different processes and functions are taking place within a parallel architecture. They interact across and between processes and domains in a network fashion. A smart city is a composite of many overlapping parallel infrastructure systems from transportation and water supply to the electrical power grid and the telecommunication networks. The components in the system are not just interacting across domains but also across scales making them systems of systems.

These complex engineered systems take the form of distributed networks. Think about the Internet of Things where many billions of devices, from smartphones to tractors to hospitals couple and decouple from the system dynamically and operate under their own internal logic. These complex engineered systems are really networks that link up many heterogeneous subsystems and components. Take for example the U.S. power transmission grid which consists of about 300,000 km of lines operated by approximately 500 companies, thus constituting a network of networks, similar to the internet.

Engineering Challenges

True complex engineered systems are distributed, no one is really in control; the whole system is a network of connections interlinking disparate devices, machines, and sub-systems. These kinds of heterogeneous environments bring new design and engineering challenges and the need to better understand and model complex systems.

The development of an IoT infrastructure across the various domains, from manufacturing 4.0, to the smart grid, smart buildings, to whole smart cities will be a huge engineering challenge of the 21st century. This development will be driven by network effects; as end users come to expect greater interoperability and seamless experiences this will drive companies and engineers to try to figure out how to build ever more complex systems of systems.

Building this next generation of secure, resilient, decentralized and sustainable technology infrastructure will require bringing in new and sophisticated models from complexity theory; a new more holistic and networked way of looking at infrastructure that is relevant for the age of the Internet of Things and the many challenges it presents. This theme explores how to leverage the power of complexity theory towards building a more resilient and sustainable technology infrastructure that is accessible to all.