SSA develops conceptual models that describe and/or represent a system.
Each model may have multiple views, such as planning, requirement (analysis), design, implementation, deployment, structure, behaviour, input and output data views. A system model can be used to describe and represent all these views.
The system model can involve either of two different approaches: architectural or non-architectural.
The architectural approach will use only one model instead of picking many heterogeneous and unrelated models. For example:
Systems architecture, using the Architecture Description Language (ADL) for both structure and behaviour descriptions.
The non-architectural approach picks a model for each view. For example:
The Structured Systems Analysis and Design Method (SSADM), using a Structure Chart (SC) for structure description.
A Data Flow Diagram (DFD) for behaviour description.