**Requirements analysis** is critical process that enables the success of a system or software project to be assessed.

Requirements are generally split into two types: Functional and Non-functional requirements.
 

## Functional


1. A functional requirement specifies “What should the software system do?”

2. Describes the functionality & services provided by a system.

3. Define a system’s reaction to particular inputs.

4. Usually easy to define.

## Non-Functional

1. A non-functional requirement places constraints on “How should the software system fulfill the functional requirements?”

2. Defines the system's properties & constraints.

3. Applied to a system as a whole.

4. Define the constraints on the action of the system e.g. timing constraints, development process constraints, etc.

5. Usually more difficult to define.

What are functional and non-functional requirements?

Requirements analysis splits into functional (what the system does) and non-functional (how the system operates) requirements.