Visualizing Early Aspects with Use Case Maps - Transactions on Aspect-Oriented Software Development - page 107

2.1 Use Case Maps

UCMs [38] are an integral part of the ITU's effort to standardize the URN [39].
UCMs are a visual scenario notation for the description of functional require-
ments and, if desired, high-level design. Paths describe the causal flow of behavior
of a system (e.g., one or many use cases). Optionally, paths are superimposed
over components which represent the architectural structure of a system (e.g.,
classes or packages). UCMs abstract from the details of message exchange and
communication infrastructures while still showing the interaction between ar-
chitectural entities. As UCMs integrate many scenarios and use cases into one
combined model of a system, it is possible to reason about undesired interac-
tions between scenarios [4], analyze performance implications [34, 35], and drive
testing efforts based on UCM specifications [6]. As UCMs show architectural
structures, various architectural alternatives can be analyzed [7, 8, 40]. Over the
last decade, UCMs have successfully been used for service-oriented, concurrent,
distributed, and reactive systems such as telecommunications systems [3, 8], e-
commerce systems [5], agent systems [23], operating systems [16], and health
information systems [1]. UCMs have also been used for business process model-
ing [40].

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…
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Path Path [C1] [C1] [C1]

Start
Point

Start
Point

End
Point

End
Point

OR-Join OR-Join

OR-Fork OR-Fork

… … …

[C2] [C2] [C2]

… … …

… Responsibility
Direction Arrow

……… Responsibility
Direction Arrow

[Guard] [Guard] [C3] [C3] [C3]

… … … … … …

…… ………

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…

…
…

…
…

…
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…
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…
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…… …… ………

AND-Fork AND-Fork AND-Fork

…

AND-Join AND-Join AND-Join IN1 IN1 IN1 OUT1 OUT1 OUT1

Static Stub &
Segments ID

Static Stub &
Segments ID

… … … … … … …

…… …… ………

… … … … … … … …

IN1 IN1 IN1 OUT1 OUT1 OUT1

Dynamic Stub Dynamic Stub

S{IN1} S{IN1} S{IN1} E{OUT1} E{OUT1} E{OUT1}

Plug-in Map Plug-in Map

Component Component

Timeout
Path

Timeout
Path

Timeout
Path

Waiting
Path

Waiting
Path

Waiting
Path

Waiting
Path

Waiting
Path

Waiting
Path

Waiting Place Waiting Place Waiting Place

Timer Timer Timer

Continuation
Path

Continuation
Path

Continuation
Path

Continuation
Path

Continuation
Path

Continuation
Path

Timer
Release
(synchronous)

Timer
Release
(synchronous)

Timer
Release
(synchronous)

Trigger
Path
(asynchronous)

Trigger
Path
(asynchronous)

Trigger
Path
(asynchronous)

Fig. 1. Basic elements of UCM notation

The basic elements of the UCM notation are shown in Fig. 1. A map contains
any number of paths and structural elements ( components ). Paths express causal
sequences and may contain several types of path nodes. Responsibilities describe
required actions or steps to fulfill a scenario. OR-forks (possibly including guard-
ing conditions )and OR-joins are used to show alternatives, while AND-forks and
AND-joins depict concurrency. Loops can be modeled implicitly with OR-joins
and OR-forks. As the UCM notation does not impose any nesting constraints,