Which document typically defines critical performance requirements qualitatively?

The ConOps (Concept of Operations) Document is designed to provide an overarching view of the operational context and needs of a system. It articulates how the system will function within its intended environment and serves as a bridge between stakeholder needs and the technical requirements that follow. One of its primary purposes is to define critical performance requirements qualitatively, outlining what the system is expected to achieve from an operational perspective.

This document focuses on capturing the stakeholders' vision, objectives, and contextual understanding of the system’s operational environment. Through narratives, diagrams, and scenarios, it helps stakeholders understand the system’s intended use and operational goals, which can include expectations around performance, usability, and user experience. That qualitative nature is essential for identifying high-level requirements without getting into detailed metrics or specific quantitative thresholds, which are typically found in more technical documents like the Technical Specification Document.

In contrast, other documents, such as the Stakeholder Requirements Document and the Technical Specification Document, usually contain more detailed and specific performance requirements, often quantifying metrics. The Risk Management Plan, on the other hand, focuses on identifying, assessing, and mitigating risks associated with a project rather than defining performance requirements.