Definitions

Before we get into the recipes, let’s agree on common terms.

Requirement	A stakeholder requirement is a statement of what a stakeholder needs. A system requirement is a statement of what the system must do to satisfy a stakeholder’s need. We will focus on system requirements in this chapter. Normally, requirements are written in an active voice using the shall keyword to indicate a normative requirement, as in The system shall move the robot arm to comply with the user directive.
Actor	An actor is an element outside the scope of the system we are specifying that has interactions with the system that we care about. Actors may be human users, but they can also be other systems, software applications, or environments.
Use case ...