Military Communications and Information Technology: A Trusted ...

Chapter 1: Concepts and Solutions for Communications and Information Systems
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Software components implement functionality described by services and
are responsible for quality of those services. They can implement new logic or
an adapter to a legacy system.
Legacy systems are monolithic systems supporting organization’s activities.
Through a layered structure, SOA allows to integrate those systems using introduced
integration techniques.
Services and legacy systems operate on organization infrastructure. This
layer includes physical resources, operating systems and virtual machines forming
an execution environment for components and legacy systems.
B. Software model
An important element of a system description is a notation used to document
an architecture design. SOA design is associated with services, components and
legacy systems layers, but operational processes and infrastructure layers are also
important for performance evaluation. The operational processes layer provides
information about the system workload and scenarios which describe how the services
are used. The infrastructure layer is included into design because it provides
information about the underlying platform on which the SOA system operates.
Language chosen to document the architecture of SOA systems is Unified
Modeling Language [15]. It’s a normalized language which supports design, specification
and documentation of artifacts created during information system development
process. UML provides comfortable mechanisms which support extending
language semantics. A set of created extensions is aggregated in a profile. UML
notation is widely accepted and used. Fig. 2 depict which layers are modeled using
the UML language.
Figure 2. Notations for SOA modeling