A sequence diagram is an interaction diagram that details how operations are carried out by showing the time-ordered sequence of messages exchanged between objects or components (the "building blocks"). It is specifically designed to visualize a single use-case scenario, illustrating which building blocks participate and how they collaborate to achieve the scenario's goal. This makes it the most suitable diagram to demonstrate to colleagues that a set of components is appropriate for implementing a specific flow of events.

A. Use-case diagram: This diagram shows a system's functional requirements from an external user's perspective, but it does not describe the internal implementation or interactions between building blocks.

C. Activity diagram: This diagram models the flow of control and activities within a system or business process, focusing on the workflow rather than the specific object interactions for a scenario.

D. Class diagram: This is a static structure diagram. It describes the system's classes, attributes, and relationships but does not show how instances of these classes behave or interact over time.

1. International Software Architecture Qualification Board (ISAQB). Curriculum iSAQB® Certified Professional for Software Architecture – Foundation Level (CPSA-F)

Version 4.2EN. (2023).

Section 4.2.2

Interaction Diagrams (Sequence and Communication Diagrams)

p. 36: "Interaction diagrams describe the communication between components/objects. They are particularly well-suited to detail the course of a use case (a scenario)." This directly supports the use of sequence diagrams for the question's purpose.

Section 4.1.2

Use-Case Diagrams

p. 33: States that use-case diagrams are used for "gathering and structuring functional requirements."

Section 4.3.2

Class and Object Diagrams

p. 38: Explains that these diagrams describe the "static structure of a system."

2. Fowler

M. (2004). UML Distilled: A Brief Guide to the Standard Object Modeling Language (3rd ed.). Addison-Wesley Professional.

Chapter 4

Sequence Diagrams

p. 47: "Sequence diagrams are the most common kind of interaction diagram... A sequence diagram shows the interactions by showing the objects and the messages that are passed between them in a use case."

3. Seidl

M.

Scholz

M.

Huemer

C.

& Kappel

G. (2015). UML @ Classroom: An Introduction to Object-Oriented Modeling. Springer.

Chapter 7

Interaction Diagrams

p. 151: "Interaction diagrams are used to model the dynamic aspects of the system. They show how a group of objects collaborates in some behavior... Sequence diagrams are particularly suitable for showing the temporal sequence of a flow." DOI: https://doi.org/10.1007/978-3-319-12742-2