【QA123】NFR 非功能性需求

背景：很多年久项目都可能会遇到系统性能或稳定性、可靠性相关的线上问题。每当组里讨论时，都会摸不着头脑；即使开发调查做了修改，有时也无法描述清楚业务场景，或由于某些限制无法重现问题。

我的理解是首先系统缺失NFR，没有对这方面有明确的需求定义。导致用户和新团队成员无法准确理解、掌握、度量系统性能等相关“非功能”需求的预期和现状。

参考：https://www.scaledagileframework.com/nonfunctional-requirements/#:~:text=NFR%20implementation%20is%20also%20impacted%20by%20the%20way,easier%20to%20implement%2C%20test%2C%20and%20maintain%20systemic%20NFRs.

‘FURPS’ is a commonly referenced set of important quality attributes: Functionality, Usability, Reliability, Performance, and Supportability [1].

NFR list is more exhaustive and includes compliance, security, resilience, privacy, accessibility, and others [2].

NFRs are modeled as backlog constraints in the framework。

 

NFRs may impact a wide range of system functionality. Therefore, they’re an important factor to consider when:

• Analyzing business epics, capabilities, and features
• Planning and building the Architectural Runway
• Refactoring to better reflect increasing solution domain knowledge
• Imposing constraints on manufacturing, deployment, support, installation, maintainability, and so on

The tools used to help develop the solution intent provide some mechanisms to establish an economic approach to define and implement NFRs:

• Compliance – Compliance drives many NFR decisions to ensure the solution meets regulatory, industry, and other relevant standards and guidelines. The solution intent often includes traceability from the system’s NFRs to those regulatory standards.
• Model-Based Systems Engineering (MBSE) – MBSE can be used to simulate the effect of NFRs and support tracing to the designs the implement them and tests that validate them
• Set-based Design (SBD) – SBD provides different options for achieving NFRs as described earlier in this article

The following criteria help define NFRs:

• Bounded – When they lack bounded context, NFRs may be irrelevant and lead to significant additional work. For example, an airplane’s flight controls should be more rigid reliability than the infotainment system.
• Independent – NFRs should be independent of each other so that they can be evaluated and tested without consideration of or impact from other system qualities.
• Negotiable – Understanding NFR business drivers and bounded context mandates negotiability.
• Testable – NFRs must be stated with objective, measurable, and testable criteria.