Non-Functional Requirement

Non-functional requirements (NFRs) constrain how systems behave—latency, throughput, RTO/RPO, privacy, accessibility—not just what features they provide. Architecture standards often encode NFR baselines teams must meet or exception. NFR neglect causes production failures despite functionally correct software.

In Practice

Larkinized LLC embeds NFR checklists in architecture review templates and reference architectures. Test plans must verify NFR acceptance criteria before go-live approval. Platform teams provide certified environments meeting common NFR tiers.

Example

An NFR specifies 99.95% availability and sub-200ms API response at peak load for customer checkout services.