Requirements Specification Explained | How to Gather, Analyse & Document System Requirements

Описание: Qualifi Level 4 Diploma in Information Technology.
Unit: 4IT01 Information Technology and IT Ethics.

In this lesson, we dive into one of the most important foundations of any IT or software project — Requirements Specification.

This lesson explains what requirements are, how to gather them from stakeholders, and how to transform them into clear, structured documentation used by engineers, managers, and clients.

What You’ll Learn in This Lesson:
▶️ What is a Requirements Specification?
Definition and purpose
User vs. system requirements
Why every project—big or small—needs a clear specification

▶️ Functional vs Non-Functional Requirements
What each type means
Real examples (e.g., encryption, privacy rules)
How both influence system design

▶️ Requirement Elicitation Methods
We break down the strengths and limitations of each method, including:
Interviews
Case studies
Focus groups
Surveys & questionnaires
Observation
Literature reviews

▶️ Requirement Analysis
Feasibility analysis
Completeness checks
Consistency checks
Use case diagrams

▶️ How to Write a Requirements Document
Understanding technical vs non-technical audiences
Organising and structuring the document
Key elements to include (functional requirements, acceptance criteria, etc.)

▶️ Formats for Requirements Specification
Natural language
UML diagrams (includes use case & class diagram examples)
Formal notations like ReqIF