Environmental Engineering Reference
In-Depth Information
Chapter 4
System Analysis and Context Assessment
Broder Breckling, Fred Jopp, and Hauke Reuter
Abstract System analysis is a theory-based approach with a wide range of practi-
cal applications for interdisciplinary co-operation that was derived from the Gen-
eral Systems Theory, as introduced by Bertalanffy and others. Formerly being
developed as an analytical instrument, it has now become also an integral part of
model development. The method starts with the delimitation of the investigated
system from the surrounding context, the specification of its compartments, key
factors, driving forces and how these interact with each other. To gain a conceptual
overview, a cause-effect diagram of a system can be constructed to sketch the
influences between the investigated components. Such a graphical examination can
be refined in a next step into a flow-diagram (flow chart) that depicts the compart-
ments, connections and controls of the system. This tool is of considerable help
when developing model systems further on the basis of differential equations, as it
enables to characterize time-dependent quantitative changes of the components as a
result of their interactions. Over the recent years, object-oriented systems analysis
(OOSA) has been established as a structural extension of the classical systems
analysis. By using the object-oriented programming approach, OOSA enables to
represent and subsequently simulate dynamic systems which change their structure
over time. We provide examples of the resulting complex interaction networks from
marine fisheries and functional plant architecture.
4.1 Systems Analysis and Context Assessment: The Starting
Point for Model Development
Systems analysis is an essential part of model development. It provides a targeted
methodology that helps to identify, represent and connect the important compo-
nents and relations which are relevant in a given context. System analytical
