Abstract: This paper elaborates the conceptual underpinnings needed to
understand and influence change in complex socio-technical systems. The nature
of causality is first addressed, followed by consideration of the nature of
complexity. It is argued that, at least from a practical perspective, the
difficulty in understanding causality increases as complexity increases. The
possibility of influencing change is addressed in terms of concepts, principles
and models for analysis and design in a range of domains or contexts.