The Engineering Mindset Part 2: Complex or Complicated? What Defines A Complex System?

Article by Chris Hamlin FREng CEng FIChemE and Penny Hamlin

Using the petrochemicals industry, Chris and Penny Hamlin explain how a complexity-based approach provides a critically different perspective and insight that can be applied to pretty much any sector, market, or organisation

Characteristic 1: porous boundaries

THE boundaries of a complex system are ill-defined, unclear, and porous with information and resources flowing across them in both directions.

The petrochemical sector epitomises this characteristic. It overlaps with other systems both upstream and downstream, and materials, energy, and knowledge flow across its boundaries. Geography and ownership muddy the waters further with companies operating across different value chains and countries.

When we think about emissions specifically, these occur at multiple places along the value chain, flowing across system and subsystem boundaries, making attribution and allocation difficult. Scope 1 emissions occur within a reasonably clear petrochemicals system boundary – the area surrounding the plant – but Scopes 2 and 3 relate to emissions that largely occur in other systems and require information to flow through the same porous system boundaries.

A complexity-based approach in action: 1

THE C-THRU project was a three-year multi-disciplinary transnational research project focused on mitigating greenhouse gas emissions from the petrochemical industry. The project recognised different system and subsystem boundaries would be needed for different purposes, and apparently obvious boundaries may be misleading. For example, the US petrochemical sector arguably operates as three distinct systems: East Coast, West Coast, and Gulf of Mexico. Similarly, the Netherlands is deeply integrated into a pan-European system and should be viewed in that context. To address this, the team used complex network modelling techniques to develop tools and models that could be analysed at different levels of aggregation and disaggregation.

Characteristic 2: constantly changing

A complex system requires continuous inputs of energy and resources to sustain it. So, the system boundary is not only ill-defined, but its context is constantly changing. Consequently, its internal structure and organisation are highly dynamic.

The petrochemical sector is in constant flux with new capacity being built and established plants being shut down all the time. Shifts in consumer demand, the constant evolution of regulations and changing investor behaviour all have an effect.

These influences are rarely system wide and are certainly not coordinated, with local economics and politics having significant impact. In some regions, the petrochemical industry itself has considerable influence, in others it is subject to external control.

Article By

Chris Hamlin FREng CEng FIChemE

Co-founder and lead advisor of research-based facilitation, training and coaching company HancockHamlin


Penny Hamlin

Co-founder and managing director of research-based facilitation, training and coaching company HancockHamlin


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