Systems concepts: a basic system must be composed of more than one what, according to standard definitions in systems theory?

Introduction / Context:
Systems theory defines a system as a set of interrelated elements working together toward a purpose within an environment. Grasping the minimal building blocks—elements and their relationships—helps in modeling organizations, information flows, and engineered artifacts accurately.

Given Data / Assumptions:

• A “system” is not a single, indivisible object; it comprises parts.
• Elements interact via relationships (flows, signals, constraints).
• Subsystems are themselves systems within a larger whole, but not required at the most basic level.

Concept / Approach:
The most fundamental requirement is multiplicity of elements. With only one element there are no internal relationships, making the concept of “system” vacuous. Subsystems may exist in complex systems, and supersystems describe the embedding context, but neither is necessary for the minimal definition. Therefore, the correct answer focuses on elements.

Step-by-Step Solution:

Verification / Alternative check:
Systems analysis texts consistently define systems as composed of multiple elements or components; subsystems are optional hierarchical groupings, not prerequisites.

Why Other Options Are Wrong:

• Subsystem: a grouping within larger systems; not required for the simplest system.
• Super system: the environment or larger containing system; a system can be defined without invoking it.
• All of the above: incorrect because only “element” is fundamentally necessary.

Common Pitfalls:
Equating organizational charts (subsystems) with the definition of a system; minimal systems need parts, not necessarily a layered hierarchy.

Final Answer:
element