Page 157 - DCAP405_SOFTWARE_ENGINEERING

Software Engineering

Notes 9.3.2 System Modeling with UML

“The Unified Modeling Language (UML) is a graphical language for visualizing, specifying,
constructing, and documenting the artifacts of a software-intensive system. The UML offers a
standard way to write a system’s blueprints, including conceptual things such as business processes
and system functions as well as concrete things such as programming language statements,
database schemas, and reusable software components.”
The important point to note here is that UML is a ‘language’ for specifying and not a method or
procedure. The UML is used to define a software system; to detail the artifacts in the system, to
document and construct - it is the language that the blueprint is written in.

Notes The UML may be used in a variety of ways to support a software development
methodology (such as the Rational Unified Process) – but in itself it does not specify that
methodology or process.

UML defines the notation and semantics for the following domains:

The User Interaction or Use Case Model: describes the boundary and interaction between
the system and users. Corresponds in some respects to a requirements model.

The Interaction or Communication Model: describes how objects in the system will interact
with each other to get work done.
The State or Dynamic Model: State charts describe the states or conditions that classes
assume over time. Activity graphs describe the workflows the system will implement.
The Logical or Class Model: describes the classes and objects that will make up the system.

The Physical Component Model: describes the software (and sometimes hardware
components) that make up the system.
The Physical Deployment Model: describes the physical architecture and the deployment
of components on that hardware architecture.
The UML also defines extension mechanisms for extending the UML to meet specialized needs
(for example Business Process Modeling extensions).

Self Assessment

Fill in the blanks:
8. A …………………… is a specification for behavior generation and the modeling process is
concerned with the development of this specification.
9. …………………… is a constructive activity and this raises the natural question of whether
the product (i.e., the model) is ‘good enough.’

10. The fundamental requirement of any ………………….. is the replication of system
behaviour within a physical environment that is as realistic as possible from the perspective
of an operator.

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