You can read further explanations on complex systems.
We will not describe here the numerous issues raised (at every level of a company: corporate strategy, marketing, product definition, engineering, manufacturing, operations, support, maintenance, etc) by the design and management of such complex systems. But every experienced business leader, manager, consultant or engineer will perfectly know what we are talking about. These issues can be summarized as:
going from local to global, i.e. mastering integration and emergence
building an invariable architecture in a moving environment.
And so, Systems Architecture is ... ?
In this context, Systems Architecture is a response to the conceptual and practical difficulties of the description and the design of complex systems. Systems Architecture helps to describe consistently and design efficiently complex systems such as:
an industrial system (the original meaning of Systems Architecture)
an IT infrastructure (Enterprise Architecture)
an organization (Organizational Architecture)
a business (Business Architecture)
a project (Project Architecture?).
Systems Architecture will often rely on a tool called an architecture framework, i.e. a reference model to organize the various elements of the architecture of a system into complementary and consistent predefined views allowing to cover all the scope of Systems Architecture. Famous architecture frameworks are for example DoDAF, MoDAF or AGATE.
Finally, Systems Architecture will consider any system with a socio-technical approach (even when dealing with a "purely technical" system). In particular, during the design (or transformation) of a system, the systems in the scope of this design (or transformation) can be divided in two separated systems in interaction :
the product, i.e. the system being designed or transformed
the project, i.e. the socio-technical system* in charge of the design or transformation of the product.
* teams, tools, other resources and their organization following strategies & methods
Click here to learn more about my research on Systems Architecture.
For more information on Systems Architecture as a discipline, you can check this book chapter (in French).
For a quality academic introduction to Systems Architecture (centered on industrial systems), you can read this paper from MIT.