Which definition of a use case is true?

A use case is a standard methodology in systems engineering and software development used to capture functional requirements. It describes the step-by-step interaction between an external user, defined as a "role" or "actor," and a system to achieve a specific, valuable goal. This structured format helps stakeholders, including Customer Success Managers, understand how a system will behave from a user's perspective to deliver a desired outcome. It is a blueprint for interaction, not a post-deployment review or a simple instruction manual.

A. This describes a value gap analysis or a customer satisfaction assessment, which compares marketing claims to actual user experience, rather than defining a system interaction.
B. This definition is incomplete. While it includes actions, it omits the critical components of a role (actor), a system, and a specific goal.
D. This describes a user manual, tutorial, or help documentation, which provides instructions for operation, not the analysis of system-actor interactions to achieve a goal.

1. Official Vendor Documentation: Cisco's Customer Experience (CX) practice heavily relies on use cases to drive adoption and value. The "Cisco DNA Center Use Cases" guide defines each use case with actors

triggers

and a sequence of steps to achieve a specific outcome

such as "Automate Network Segmentation." This aligns with the definition of interactions between a role and a system to achieve a goal.

Source: Cisco

"Cisco DNA Center Use Cases

" Document ID: 119402

Section: "Use Case Overview."

2. Peer-reviewed Academic Publications: The foundational concept of use cases was introduced by Ivar Jacobson. His work defines a use case as a description of a set of sequences of actions that a system performs to yield an observable result of value to an actor. This is the academic basis for the definition in option C.

Source: Jacobson

I.

Christerson

M.

Jonsson

P.

& Övergaard

G. (1992). Object-Oriented Software Engineering: A Use Case Driven Approach. Addison-Wesley. Chapter 6: "Use-Case Modeling

" pp. 127-132.

3. University Courseware: Reputable computer science programs teach this standard definition. For example

MIT's courseware on software engineering defines a use case as a specification of a sequence of actions

including variants

that a system can perform by interacting with outside actors to provide a result of value.

Source: MIT OpenCourseWare

"6.170 Software Studio

" Fall 2005. Lecture 4: "Requirements Analysis

" Section: "Use Cases."