Use Case Diagram

Actor-to-goal. Dated, but still the clearest way to show scope boundaries.

• Format.puml
• Length25 lines
• Includesnone

The source

25 lines of PlantUML, and needs nothing beyond the bundled engine. Copy it, or open the template inside Gnomon and render it as it is.

@startuml

title Use Case Diagram

left to right direction

actor "User" as user
actor "Admin" as admin

rectangle "System" {
  usecase "Login" as UC1
  usecase "View Dashboard" as UC2
  usecase "Manage Users" as UC3
  usecase "Generate Report" as UC4
}

user --> UC1
user --> UC2
user --> UC4

admin --> UC1
admin --> UC3
UC3 ..> UC1 : <<include>>

@enduml

Others in UML and standard diagrams

• Sequence DiagramThe highest-value diagram in this list. Time runs down; participants across.
• Activity / Flow DiagramEarns its place when there are real branches and joins.
• Class DiagramBest used for a single bounded context, not a codebase.
• State DiagramForces the awkward questions about duplicate and out-of-order events.
• ER DiagramCardinality is the part people get wrong. Write it explicitly.
• Mind MapFor structuring thinking, not for documenting a system.
• Gantt ChartPlans, not architecture, but it renders from text, so it diffs in review.
• JSON VisualizationVisualises a JSON payload: handy in an API design review.
• Work Breakdown StructureWork breakdown. Useful for scoping a piece of delivery.