Technique for capturing potential functional requirements that employs the use of one or more scenarios that convey how the system should interact with the end user or another system to achieve a specific goal.
- NOTE: Typically use cases treat the system as a black box, and the interactions with the system, including system responses, are as perceived from outside of the system. Use cases are popular because they simplify the description of requirements, and avoid the problem of making assumptions about how this functionality will be accomplished
Source: ANSI/ISA–99.00.01–2007, Security for Industrial Automation and Control Systems, Part 1: Terminology, Concepts, and Models, 29 October 2007. National Standard