Disciplined Agile

Quality Requirements and Agile

What is quality? Answering this question can be difficult because quality is in the eye of the beholder, or as Gerry Weinberg was wont to say, “Quality is value to some person.” The implication is that we need to work closely with our stakeholders to discover what quality means to them. Quality requirements—also known as nonfunctional requirements (NFRs), system-wide requirements, quality of service (QoS) requirements, or “ilities”—address issues such as security, availability, reliability, performance, usability, and other key concerns. Figure 1 shows potential categories of quality requirements.

Quality Requirements

Figure 1. Potential categories of quality requirements (click to enlarge).

Quality requirements drive many of the acceptance criteria for our functional requirements as well as architectural decisions and test strategy decisions. As you can see in the Figure 2, the process goal diagram for Explore Scope, there are several ways to explore and capture quality requirements. You generally want to explore quality requirements as early in the life cycle as possible, and be prepared for them to evolve throughout your initiative as your situation evolves.

February 2022

2021 Project Management Institute Explore Scope v5.3 Explore Purpose Ideathon Ideation board Impact map Mind map Modified impact map Outcome Really round robin Value proposition canvas Explore Usage Design sprint (User experience (UX)) Epic Persona Unified Modeling Language (UML) use case diagram Usage scenario Use case User story User story map Explore the Domain Domain/conceptual model Event storming Glossary Logical data model (LDM) UML class diagram Explore the Process Business process diagram Data flow diagram (DFD) Flowchart UML activity diagram UML state chart Value stream map Explore User Experience (UX) Design sprint (user experience (UX)) User interface (UI) flow diagram UI prototype (high fidelity) UI prototype (low fidelity) UI specification Explore General Requirements Business rule Context diagram Feature statements Impact map Mind map Modified impact map Shall statement Value proposition canvas Explore Quality Requirements Acceptance criteria Explicit list Technical stories Apply Modeling Strategy(ies) Agile Modeling (informal) sessions Open space Joint application requirement (JAR) sessions Interviews Choose a Backlog Management Strategy Lean backlog Agile backlog Requirements (product) backlog Unsequenced backlog None Level of Detail of the Scope Document Outcome driven Requirements envisioning (light specification) Detailed specification No document

Figure 2. The Explore Scope process goal diagram (click to enlarge).

February 2022

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