Requirements Modelling Module Notes

A system is an organization of discrete components connected to achieve a purpose. Examples include:
- Education system
- Legal system
- Computer system
- Human body

Environment and Boundary: Systems operate within an environment defined by a boundary that separates them from non-system components.
Inputs and Outputs: Systems transform inputs (data, commands) into outputs (products, information).
Control: Feedback mechanisms help maintain system function, with systems classified as open-loop or closed-loop based on feedback structure.
Synergy: The whole is greater than the sum of its parts, revealing emergent properties not present in individual components.

Negative Feedback: Stabilizes a system (e.g. thermostatic control).
Positive Feedback: Reinforces changes leading to extremes (e.g., social media engagement).

Defined as the combined power of a group that exceeds the sum of individual efforts. Results in properties that emerge only at the system level.

Requirements are foundational elements detailing what a system should do and the constraints under which it operates. They reflect user needs and objectives.

Functional Requirements: Describe system services and expected functions.
Non-Functional Requirements: Detail constraints related to performance, usability, security, etc.