5 Key Non-Functional Requirements Every System Designer Should Know

In the world of system design, we often focus heavily on functional requirements— what the system should do. However, equally important are the non-functional requirements (NFRs)—how the system should perform its functions. NFRs define the quality attributes that can make or break your system's success, regardless of how well it fulfills its core functionality.

This article explores the five most critical non-functional requirements that every system designer should understand, prioritize, and implement.

Understanding Non-Functional Requirements

Before diving into specific NFRs, let's clarify what they are and why they matter:

Non-functional requirements define quality attributes and constraints that specify criteria for evaluating the operation of a system, rather than specific behaviors. While functional requirements describe what a system does, non-functional requirements des…